On a desultory afternoon last month, Representative Tom Davis cruised through the cloakroom on his way to the floor to manage a bill, a mobile telephone pressed to his ear as he waved me to follow. We entered the chamber where war, slavery and impeachment have been debated, and he headed to the lectern while I sat a couple rows back. Davis clicked his phone shut and addressed the mostly empty chamber: “Mr. Speaker, I rise to speak on H. R. 5683, the Government Accountability Office Act of 2008.”

After a couple of minutes, Davis was back in the cloakroom, plopping down in a chair, propping his feet up on a coffee table and popping open a Diet Coke. He sighed at the tedium of the exercise and then thought back to the first time he ever managed a bill on the floor. It was 1995, and he was a freshman Republican congressman from Virginia, swept into office by Newt Gingrich’s revolution. “What a thrill,” he said, his eyes lighting up at the memory. “I thought, You know, maybe I belong here. Now it’s kind of like, Oh, I gotta do this?”

A few minutes later, in fact, an aide emerged from the House chamber to ask Davis if he wanted to manage the next bill, H. R. 6575, the Over-Classification Reduction Act. Davis shook his head no. “In the old days, you’d jump at the chance to manage a bill,” he told me.

No more. The revolution is over, the thrill is gone and the Republican brand under President Bush has, in Davis’s view, been so tarnished that, as he likes to say, “if we were a dog food, they would take us off the shelf.” These will be Davis’s last few weeks in Congress. He decided against re-election, disaffected by the partisanship, by a process he calls broken, by a party he considers hijacked by social conservatives. “We’re just not getting much done,” he said.

Another aide sat down and told him there would be three more votes. “They’re all yes votes,” the aide said.

Davis laughed. “Let me make up my own mind!” he said in mock protest. Gesturing to me, he said, “I’ve just been telling this guy I’m an independent agent!”

Then he asked for a list of the three bills to see if he really did want to vote yes: A nonbinding resolution “recognizing that we are facing a global food crisis.” O.K., Davis said puckishly. That’s a yes.

A second resolution “expressing the sense of the House of Representatives that the emergency communications services provided by the American Red Cross are vital resources for military-service members and their families.” O.K., another yes.

A third resolution “condemning the use of television programming by Hamas to indoctrinate hatred, violence and anti-Semitism toward Israel in Palestinian children.” A third yes. “They read me pretty well,” Davis said, chuckling at the absurdity of it all.

Then he shook his head. Three resolutions offering platitudes, none of them carrying the force of law, none of them actually doing anything. Davis asked for a list of all 20 bills on the floor that day — naming post offices, recognizing the anniversary of Bulgaria’s independence, honoring an old American war sloop.

Davis wanted me to have the list. “Tell them about the important work we’re doing while Rome burns,” he said.

After 14 years in Congress, Tom Davis is giving up his place in the bucket brigade. Someone else will have to put out the fire. If anyone wants to try.

For Republicans like Davis, these are gloomy times. While John McCain’s pick of Sarah Palin as his running mate energized the party after a long stretch of depressing developments, the most optimistic Republican strategists still expect further losses in Congress even if McCain wins the White House.

The way Davis sees it, the system has become dysfunctional. Bush has so destroyed the party’s public standing and Congress has become so infected with a win-at-all-costs mentality that there is no point in staying. “You know, the Cubs fans used to put the bags over their heads,” he told me when we met for eggs at Mickey’s Dining Car in St. Paul the first morning of the Republican National Convention. “That’s what I feel when you say you’re from Congress, because there are just so many things we’re not doing.”

This might be dismissed if it came from a fringe player on Capitol Hill, but for years Davis was one of the rising stars, a quintessential inside player who as part of the leadership managed to steer his party to election victories in even-numbered years while working with Democrats on legislation in odd-numbered years. He ran the House Republican campaign committee for two elections and later bypassed more senior congressmen to become chairman of the House Government Reform Committee until his party lost control of Congress. He spent a lifetime getting to this point and is now washing his hands of it, even as he foresees a fiscal reckoning after so much unbridled government spending, most recently to bail out Wall Street.

“When you get the majority, the leadership team sits around the table, and the first question the winners ask, sitting in this ornate room, is ‘How do we stay in the majority?’ ” he said. “Now the members, a lot of them, are willing to tackle these issues, but they elect leaders, and the leaders’ report card is: Do they get their members re-elected? You see what I’m saying? And the minority, by the way, sits in a little less ornate room, a little smaller room in the Capitol, and they say, ‘How do we get it back?’ And so for every issue it’s ‘Do we cooperate or do we try to embarrass them?’ Very few times they cooperate.”

As for Bush, Davis long ago lost faith. “He’s a disappointment,” Davis said. “How else do you say it?” In his view, Bush grew isolated and surrounded himself with people who made bad decisions. The president, he lamented, failed to effectively tackle a rising deficit, Medicare and Social Security. He rose to the occasion after terrorists attacked on Sept. 11, 2001, but not after Hurricane Katrina smashed into the Gulf Coast. “I would vote for him again against John Kerry; that’s not an issue,” Davis said. “But I’m disappointed just in terms of his stewardship. I wrote the Katrina report. Just the fact that he wasn’t down there the next day and he flew over it in Air Force One to get a view of it — that, to me, is not leadership.”

Davis is one of 26 Republicans who have chosen to retire from the House this year, many of them moderates like him, compared with 6 Democrats. “There’s no question we’re a dying breed,” said Representative Jim Ramstad of Minnesota, who is also giving up his seat.

By one measurement, Congress is the most polarized it has been in a century. Sean Theriault, a scholar at the University of Texas at Austin who just published a book called “Party Polarization in Congress,” analyzed voting patterns to put each two-year session on a scale. In his study, Congress in its Watergate session from 1973-74 was 29 percent polarized. By 2005-6, it was 46 percent, the highest since the most polarized Congress in history, back in 1905-6, when it reached 48 percent on Theriault’s scale.

“The electoral campaign has infiltrated the legislative process,” Theriault told me. “Congressmen used to campaign at home, win elections and then come to Washington” to grapple with the issues of the day. Now, he said, “They’re just looking to gain advantage wherever they can.”

This evolution has been fueled by migration patterns, demographic shifts and, many argue, redistricting. Most lawmakers represent safe districts, giving them little incentive to tack to the center and work together. Indeed, many incumbents worry more about “being primaried,” as they put it, drawing a primary challenge from within their own parties for being insufficiently orthodox.

Davis represents one of those few districts that can go either way, a cluster of wealthy suburbs outside Washington rapidly transformed by immigration. A third of the residents are from minority groups and a quarter speak a language other than English at home. Bush edged Kerry by 2,000 votes there in 2004, while the Democrat Jim Webb trounced Senator George Allen in 2006. Davis has not drawn a first-tier challenger since winning his seat in 1994 but saw a warning sign two years ago when he won with just 55 percent after outspending a little-known Democrat 10 to 1.

“I had a guy say to me: ‘Look, I’ve voted for you before, I’ll probably vote for you again. But not this time. I’m sorry, but you’re just collateral damage,’ ” Davis told me. He recalled another voter telling him: “ ‘I like you, you’re good. But I’ve just got to send a message to Bush.’ I said, ‘Look, give me a letter, I’ll take it to him for you personally.’ ”

The party has taken such a beating because of Bush and Congressional scandals that Davis took it upon himself to sound the alarm last spring in a 20-page memo to the Republican leadership, calling the atmosphere “the worst since Watergate,” even worse than 2006. “Failure to fundamentally change the G.O.P. brand can lock us into a long period of minority status,” he warned. The memo became public, and some Republican colleagues were irked with Davis. But none, he says, disputed his analysis.

For Davis, who is 59, the decision to leave came after a series of personal blows. The loss of the majority in 2006 cost him his chairman’s gavel. His wife, Jeannemarie Devolites Davis, lost re-election as a Virginia state senator in 2007. And he gave up his ambition to run for the United States Senate this year when his state party decided to choose its nominee by a convention dominated by conservatives rather than a primary open to Davis’s independent supporters.

So in recent weeks, he has become the picture of Republican frustration. “You know, when I was first elected, I think I would have done or said anything just to get elected,” he told me. “I just wanted to win. But the longer you stay in, you don’t feel that anymore.”

His wife interjected. “It’s my influence over him,” she joked, knowing that some in Virginia blame her for making him quit. A 10-year legislator in her own right, Devolites Davis says politics has grown too corrosive. “When you get to a legislature you start compromising yourself,” she said. “You get caught after a while. You have to keep up with how you’re changing to please this person and that person. And you come to understand you can’t please everyone. It’s impossible.”

If anyone ever tried to please everyone, it was Tom Davis. I first met him 22 years ago when he was a local supervisor in Fairfax County outside Washington and I was a rookie reporter. Davis was the boy wonder of Virginia politics, whip-smart and funny, affable and ambitious. He had an easy smile and could make fun of himself. He was a deal maker, a consensus builder who brought Democrats and Republicans together. He had future written all over him.

I remember hanging out with Davis in a backroom of the county headquarters talking politics during breaks in zoning hearings. Davis knew election results the way other boys knew baseball statistics. (Actually, he was a baseball fiend and knew both.) He could expound on campaigns down to the precinct level in, say, Oklahoma or New York. He knew how much of the vote Richard Nixon received in the District of Columbia in 1972 and how the Atlanta suburbs were changing politically. I had little doubt that he would be a senator or speaker of the House someday.

Davis came at this by virtue of his grandfather, Clarence Davis, who was elected attorney general of Nebraska at 25. Born in Minot, N.D., Thomas M. Davis III moved at age 5 to the Washington suburbs when his grandfather went to work for the Eisenhower administration. Davis remembers his grandfather coming back from the Republican convention of 1956 with “I like Ike” buttons. “I’m 7 years old, he started talking politics and something clicked,” Davis told me. “There was an interest there unlike anything that I ever experienced, except for baseball, and I clearly wasn’t good enough for baseball.”

The young boy devoured everything he could about politics, down to the footnotes. He charted his first elections in 1958 at age 9, although his mother made him go to bed before West Coast returns came in. In 1960, he volunteered for Nixon. He later became a Senate page and collected autographs from Barry Goldwater and Mike Mansfield. Jim Ramstad, then a Senate messenger, said Davis stood out. “He already had developed his encyclopedic knowledge of political data,” Ramstad told me. “I thought at the time, This guy’s going to be in Congress someday.”

What Davis did not tell Ramstad about was the trauma at home. His father was a college professor who grilled his son about presidents on the ride home from picnics along the Potomac River. But he was also an alcoholic who stormed about in drunken stupors, chasing his wife onto the front lawn as young Tom ran after them to protect her. His father left home and twice wound up behind bars for petty larceny, shoplifting and public drunkenness.

Davis’s housing stipend from the Capitol Page School went to pay the mortgage, but when he left for Amherst College on a scholarship, the checks stopped coming, forcing his mother to sell their house and take a two-room apartment. When he came home from college, his father had been released from prison, and there was no room for young Tom, so he slept on a neighbor’s couch. Even today, Davis does not drink, and those close to him attribute his conciliatory political style to early experiences with his father.

After an internship in the Nixon White House, stints in the Army and Army Reserves and a law degree from the University of Virginia, Davis embarked on a political career. He notched the first of 11 straight election victories in 1979, when he won a seat on the Fairfax County Board of Supervisors at 30. “I ran it like a presidential race,” he recalled. “If a new 7-11 opened, I was there to sip the first Slurpee. I was 24-7.” Over the next 12 years, he pushed through a no-smoking law, opened a county homeless shelter, drafted an affordable-housing ordinance and made friends on both sides of the aisle. When he ran for board chairman in 1991, he ousted the Democratic incumbent in a landslide, then wiped out a $200 million budget shortfall with a bipartisan plan that spread the pain and generated a unanimous vote.

He mastered the skill of appearing to be all things to all people. “It was Tom Davis who taught me to vote yes on the amendment and no on the main motion so I could be on both sides of the issue,” one Democrat who likes him told me with professional admiration. When that did not work, he would be accused of playing both sides. And by his own admission, he did not take criticism well. Lots of reporters and politicians have stories of searing phone calls.

I remember the night voters rejected his proposal to levy a restaurant tax to help address the budget crisis. He saw me in the county building and asked to read the article I had just filed, then grew hot as he complained that he should not be blamed for the defeat. His chief aide had to pull him away, nudging him out to the parking lot to go home. He got in his car but, after the aide drove off, got out again, stalked back into the building and resumed railing at me.

But Davis did not stay mad for long, and it was hard to stay mad at him. He understood how the game was played and realized that holding grudges was never smart. And at least some of his temper was calculation. Once I bristled when he accused me of adopting a critic’s spin. He instantly backed off. “How can I make you feel guilty without ticking you off?” he asked. “That’s what I’m trying to do.”

Tom Davis arrived in Congress with the Gingrich class of 1994, again ousting an incumbent Democrat, but he was hardly a revolutionary. Davis was a business-oriented Republican animated by economic competitiveness, fiscal responsibility and bipartisan problem solving. Right away, he teamed with Democrats to tackle the financial collapse of city government in Washington. “He was basically mayor by default,” his longtime aide, Howard Denis, told me. Davis worked with President Bill Clinton’s aides and other Democrats to form a financial-control board to get the city back on its feet. “We moved it through a lot of land mines,” he recalled. “That taught me right away up here — if that had been a partisan deal, it never would have gone.”

That is the model he says is missing today. As coarse as politics seemed in the 1990s, Davis remembers it as a productive period when Clinton and Gingrich and their parties actually did business. They overhauled welfare and eliminated the deficit. Davis managed to close the long-hated Lorton prison in Virginia and to push through legislation allowing children from the District of Columbia to pay in-state tuition at any state college in the country. Divided government, he told me, may actually be better for getting results. “If you’re solving a big problem, whether it’s welfare reform or Social Security, you want every perspective at the table — not so they can veto it, but so you can get everyone involved,” he said.

Since Bush took office, with Republicans in charge of Congress for most of the last eight years, there has been little appetite for reaching across the aisle. The two sides, he says, are so divided that they are incapable of recognizing what he sees as the looming crisis of our time — the massive debt accumulated during the Bush years. The only time the two parties agree, he noted scornfully, is to spend vast sums of money to prop up the economy and win re-election. He voted against the economic stimulus package last spring as a result. “The fiscal thing is awful,” he told me. “When you’re running $300, $400 billion a year in debt every single year and nobody wants to face the issue, the time is coming pretty soon where it’s going to have a huge effect on things.”

The collapse of Wall Street reinforced his view that Washington has fallen down on the job. “Nobody keeps an eye on anything unless it hurts the other party,” he said. With the situation now threatening widespread economic damage, Davis told me in late September that he expected he would have to go along with a massive bailout proposed by the Bush administration. But he fretted that it would only worsen the nation’s balance sheet and tie the hands of the next president. “This compounds the whole deficit issue,” he said. “It’s huge. I listen to McCain and Obama and they mean well. But there’s no money to do anything.”

He says that members of both parties shy away from the hard stances, like raising the retirement age for Social Security or ruling out new tax cuts. And Davis knows he went along with bad decisions for the same bad reasons others did. One example he cited was a change allowing elderly Americans to receive Social Security benefits even if they are still working. “We made it worse, and I voted for it,” he said ruefully.

Davis, of course, was never above politics. He made a national name for himself beating Democrats when he was chairman of the National Republican Congressional Committee from 1998 to 2002, picking candidates, raising money, setting strategy and traveling the country. “That was the job I was made for,” he told me wistfully. His detailed knowledge of districts paid off. He held the Republican majority in 2000 and 2002 but clashed over strategy with fellow House Republican leaders and with Karl Rove, Bush’s political guru. “He looks through the cultural prism of divide and conquer,” Davis said. “I look at it like, ‘Look, the world is changing and we need to appeal to these people.’ We had a different view of how the coalitions should evolve.”

(Rove disputed that, saying his strategy was to expand the universe of Republican voters to reach Hispanics, Jews, Catholics and exurbanites. “To suggest that our focus was inside not outside — I could not get him to be as outside as we wanted him to be,” Rove told me.)

To conservative House leaders, Davis seemed mercurial and unreliable. He voted to authorize the Iraq war and to expand counterterrorism powers but broke with Bush on stem-cell research and children’s health insurance. He voted against same-sex marriage but for employment-discrimination protection for gay and lesbian workers. He voted for trade pacts and tax cuts but against drilling in the Arctic National Wildlife Refuge. He voted for a fence along the Southern border and also for a ban on assault weapons.

“Tom has taken some arrows for being willing to work across party lines,” Mark Warner, the former Democratic governor who would have been Davis’s opponent had he run for Senate, told me recently. “He was always a hard-core fighter for increasing the Republican majority. But he also thought you could have professional differences without making it personal.”

Davis had to give up the campaign committee because of a term limit, but he said it was clear House leaders were just as happy to see him move on. His payoff was chairmanship of the Government Reform Committee, a prime post for someone who represents so many federal workers. He quickly forged a partnership with the top Democrat, Representative Henry Waxman of California. “When he became chairman, he said to me a lot of the issues that would come before our committee would not make the difference between Democrats and Republicans and we should try to work together,” Waxman told me. “And when we have differences, we’ll battle it out.”

Davis and Waxman did team up for a high-profile investigation into steroid use in Major League Baseball. But as Davis walked out of their first hearing, an aide told him that Representative Tom DeLay of Texas, then the powerful House majority leader, was waiting in his office. “Have you heard of Terri Schiavo?” Davis recalled DeLay asking. Schiavo, a brain-damaged woman kept alive on a feeding tube, had become a cause célèbre for the right. DeLay wanted Davis to subpoena the woman and her medical tubes, effectively ordering that she be kept alive while conservatives tried to pass legislation intervening in the case. Davis balked. “I asked him, ‘Can’t you get Frist to do it?’ ” he told me, referring to Bill Frist, then the Senate majority leader. “I was looking for any way not to do it.” But Davis was the only House chairman with the power to issue a subpoena unilaterally. DeLay insisted. Davis relented. “I signed it,” he said. “I serve at the pleasure.”

He brought the episode up with me as an example of the trade-offs for a congressman serving in the leadership and an explanation for why he was not destined to rise higher in the ranks. “There are costs to being a leader,” Davis said. “You’re not an independent actor as a leader.” Eventually, he said, he refused to extend the subpoena as long as DeLay wanted.

Tension flared as well over Davis’s efforts to engage in oversight. He produced a report blistering the Bush administration for its botched response to Katrina. And he pushed DeLay to investigate lobbying corruption. “I said: ‘Tom, this is the biggest scandal to hit Congress in 30 years and we do nothing? It’s just not credible. We are not just an appendage of the administration,’ ” Davis told me. “He understood. He wasn’t happy about it.”

Neither were Democrats, who accused Davis of not going far enough. “We were very discouraged our committee didn’t do more oversight when Republicans were in power,” said Waxman, who added the word “Oversight” to the committee’s name after taking charge last year. “When Bush became president, even under Chairman Davis, there wasn’t a scandal too big for them to ignore.” While crediting Davis for taking on Katrina, Waxman lamented that he did not dig deeply enough into the White House role.

Other critics said Davis was too cozy with K Street lobbyists and the federal contractors who populate his district. The Washington Post called into question Davis’s relationship with a consulting firm that advises technology companies seeking government work, a firm that was formed by a close friend and employed Davis’s wife. Davis erupted at the story. When he later ran into one of the reporters at a supermarket, Davis loudly berated him. “I told him he was scum, basically,” Davis told me. “I told him it was a scummy thing to do and I hope he felt good about it and I hoped he’d rot in hell.” He paused at the memory. Davis usually regrets his outbursts after he cools down. “If it was just me, that’s fine,” he said. “But on her, I get very, very defensive. Why do you have to drag her into it?”

Tom Davis and Jeannemarie Devolites met in the 1990s as she was building her own political career and he became a mentor. After their respective marriages fell apart, they became engaged and married in 2004. But their partnership rankled some Republicans, and the couple found ugly and mean things written about them on the Internet.

Last year, Devolites Davis lost re-election as a state senator in an increasingly Democratic district. One person close to Davis called it “vendetta politics,” saying “the party line was ‘we can’t get him, but we can get her.’ ” Both Davises took it hard. The election came only weeks after Republicans decided on a convention to pick their United States Senate nominee in 2008. The party, Davis declared, “gave me the middle finger.” He announced he would not run for Senate. In January, he said he would not to run for re-election to the House, either.

“He’s entitled to some resentment,” said Gerry Connolly, the Democrat who is now favored to win Davis’s seat. “This is somebody who did a lot for party building, certainly at the national level and certainly here in Virginia at the state and local level. And he saw it all slipping away.”

Jeff Frederick, who took over as chairman of the Virginia Republican Party after the convention decision, told me: “People statewide sometimes forget this — Tom Davis has been a team player. Although he’s sometimes in intense battles, when it comes time to close ranks, he closes ranks and fights for the team.”

It may be that fighting for the team is what has taken such a toll on Davis. The cost of loyalty — reconciling his own centrist, pragmatic instincts with the demands of a conservative party — seems to weigh on him. “You’ve got to, quote, ‘play the game,’ ” he told me. “If you want advancement, you’ve got to adhere to the party lines on a lot of issues.”

During one of our conversations last month, I asked him whether it was a mistake to invade Iraq. He stared at me intently without answering for quite a while, as if trying to decide whether to say what he really thought. On my tape, it counts out to eight long seconds before he spoke, but at the time, it seemed longer. Finally, he said softly: “I don’t want to go there. We’re where we are. I don’t think we need to revisit that issue. Probably the facts speak for themselves.”

Then he tried to explain his vote. “Our vote to go to war was a vote to give permission,” he said. “It wasn’t a vote to go to war. It wasn’t a declaration of war. The president was trying to get inspectors in there and he said, ‘Look, we’re going to do this the hard way or the easy way.’ And if you don’t stand behind the president in those circumstances, you kind of pull the rug out from under him. You know what I’m saying? Now, if you knew it was going to come out this way, that’s a different answer.”

At the same time, he seems angry his team did not stand behind him, particularly on his effort to give the District of Columbia a full-fledged member of the House. Davis tried to address longstanding Republican objections by balancing what would be a new safe Democratic seat by adding a safe Republican seat in Utah at the same time. It passed the House, but Republicans filibustered in the Senate. And he took it as a sign. “The party leadership,” he said, “has kind of signaled that since I was not a hard-core social conservative, any advancement was going to be over them, not with them.”

For a smart, connected guy like Davis, doors will open. After 29 years in public office, he said he wants to earn money before retirement, spend time with his wife and go to more baseball games. He has started teaching. I went to one of his first classes at George Mason University. There was the boyish enthusiast I remembered from the 1980s, lecturing on cultural politics of the South and rattling off election results over the past century. At one point, discussing voting rights for felons, he allowed that not all felons are Democrats. “There are a lot of Republican felons,” he said. “I served with them in Congress.”

But the students did not come alive until he threw the discussion open for questions and they asked about Sarah Palin. “The base hated McCain; it was a marriage of convenience,” Davis told them. “What are the negatives? What about her résumé? I got through it in about 10 seconds. Does that hurt? He’s the guy running on experience — ‘3 a.m., I’m the guy.’ And she’s a heartbeat away.” On the other hand, Davis said, Republicans can argue they would make history just as Democrats would with Barack Obama. “She helps on the change issue, doesn’t she? She’s sure change, isn’t she?”

After class, we headed over to the student union. Davis ordered a Double Whopper at Burger King, hold the bread in deference to his Atkins diet, but yes to the onion rings. At that moment, McCain had jumped up in the polls, but Davis said he was not having second thoughts about quitting. He could be more productive elsewhere, he said. And while he still loved the game, he said, he was tired of the rules. “We all bob and weave,” he said. “Everybody bobs and weaves in this business. I’ve bobbed and weaved with the best of them.”