On a recent Saturday night, state Sen. Linda T. "Toddy" Puller, D-Fairfax, and Jean R. Jensen, former secretary of the State Board of Elections, met for dinner at an Alexandria bistro. The first course: U.S. Sen. Mark R. Warner, D-Va.

Warner knew that his old pals had been planning an evening out, and, intent on catching up, invited himself for a quick drink before heading elsewhere.

As Warner, casually dressed in a leather jacket and slacks, nursed a glass of white wine and picked at an appetizer, the trio parsed the latest political developments, including the special election for a state Senate seat in Fairfax County that Democrat David W. Marsden had won in a squeaker.

"He was trying to stay involved with the people of the state; to do what he can to make sure that the Democrats can be successful," Puller says of the get-together with Warner.

It was vintage Warner: The senator, simultaneously frantic and focused, rarely passes on even a fleeting opportunity to tend his base -- a balky and, because of the all-or-nothing battles in Washington, increasingly restless blend of true-blue Democrats, independents and centrist Republicans.

The river separating the nation's capital from the commonwealth was once a boundary between two very different worlds. But a year into his freshman term in the Senate, Warner is facing in Washington, writ large, the sharp partisan divide that for more than two years threatened his governorship.

The self-styled "radical centrist" remains hopeful that the Senate, on some issues, can embrace the bipartisanship that allowed him, during his last years in Richmond, to achieve the unthinkable: a $1.4 billion tax increase from a Republican-controlled legislature for schools, police and welfare.

But there have been jarring bumps over the past 13 months for Warner, a once and perhaps future presidential prospect, according to handicappers at outlets ranging from Daily Kos and CNN to the Los Angeles Times.

Early in his term, personal and political friends publicly pelted Warner for ducking a stance on a measure, now moribund, that could make it easier to unionize the workplace. And more recently, Warner's image as an independent-minded business guy preoccupied with fiscal discipline was dented by his party-line support of health-care reform and increased federal spending.

"Do I like it?" a relaxed Warner says of the criticism. "No. If I wasn't willing to take it, I'm in the wrong business."

But Warner is dishing it out, too. He has faulted, if only a little bit, the Obama White House for not doing a better job of laying out for the nation that the economic-stimulus plan isn't just about government spending; that it includes tax breaks and job-creation inducements.

"I think the stimulus money was very poorly explained," Warner says.

Warner still is making the adjustment from a chief executive who for four years largely set the pace for home-state politics and policy to one of 100 members of an increasingly fractious, tradition-bound legislative body where power is rooted in seniority. For example, Warner -- now the junior senator from Virginia -- beams wistfully when addressed by the honorific that he surrendered four years ago: governor.

Warner confesses to a "real frustration with the overall process" in the Senate but says he has "found some lanes where you can get stuff done."

The marquee stories out of Washington overshadow Warner's continuing efforts to strike middle ground on the issues with which he has long been synonymous, such as finance and health care. And last month, he sought to put some distance between himself and President Barack Obama, urging him to do more to control spending.

For example, Warner is working closely with Sen. Bob Corker, R-Tenn. -- a fellow Banking Committee member, multimillionaire, bicyclist and occasional drinking buddy against whom Warner campaigned in 2006 -- on a complex element of a now-apparently doomed bipartisan overhaul of the financial regulatory system. They are looking to shift the power to supervise ailing banks and investment firms, those deemed too big to fail, from regulators to a new bankruptcy court. Corker says his bond with Warner -- the senators are considering joint appearances along the Tennessee-Virginia border spotlighting regional attractions -- could be a microcosm of what the Senate should be.

"I know you can't get there if others do not develop these kinds of relationships," Corker says. "I hope that ours will continue to evolve. I think partisan politics will pull us in places that are not good for our country."

But by early February, partisan rancor had paralyzed efforts at financial reform. The Banking Committee chairman, Sen. Christopher J. Dodd, D-Conn. -- for whom Warner once worked as an intern and who was among the mourners at the recent funeral of Warner's mother, Marjorie -- announced an impasse with Republicans on a sweeping update.

However, Corker and Warner say they're still talking. And last week, Dodd was at the table, renewing hopes for a bill.

The Senate health-care bill, fodder for disappointed Warner allies like former U.S. Sen. Harry F. Byrd Jr., I-Va. a living emblem of fiscal conservatism, included cost-cutting provisions pushed by Warner and other centrist Democrats -- and endorsed by the Republican-leaning Business Roundtable and the reliably Democratic AFL-CIO.

"The centrist group in the middle has got to be willing to hang together," says Warner, adding that the loss of Senate Democrats' 60-seat supermajority will put pressure on the parties to cooperate.

"Fifty-nine votes forces bipartisanship -- and that's good."

However, Warner's Virginia friends, particularly Republicans who backed him for governor in 2001 or for senator two years ago, expect him not only to reach across the aisle but also to draw a line with Democrats, including Obama.

Garth Wheeler, former president of the Virginia Fraternal Order of Police, says that on health care, "I don't think [Warner's] listening to Virginia."

Paul Galanti, a Vietnam War hero and veterans advocate, says: "I just wish he had fought his party a bit on all these extreme-left proposals rammed down by Obama and that crowd. He should be a leader."

But others say Warner is exactly that. For example, Senate Majority Leader Harry Reid, D-Nev., selected Warner as the caucus emissary to big business, regularly sounding out executives on such issues as health care, energy and transportation.

Warner does so at private, informal luncheons -- the menu, typically, is takeout deli sandwiches and office-brewed coffee.

Warner and several other senators have met with corporate bigs like Richard H. Anderson of Delta Air Lines, Safeway's Steve A. Burd and Thomas F. Farrell II of Richmond-based Dominion, a top supporter of Gov. Bob McDonnell, a Republican.

But this is typical duty for Warner -- the kind of gig that allowed him to cobble a bipartisan coalition that, at least in Richmond, created the impression that government occasionally can work.

David "Mudcat" Saunders, a Democratic strategist who advised Warner in the governor's race and has occasionally clashed with his former client, says: "Mark's got this grand dream of building a coalition of moderate Republicans and moderate Democrats, and it's a dream worth dreaming."