U.S. Sen. Mark Warner chats on the Washington Post Live show earlier this month in Charlotte, N.C. (Marlon Correa/THE WASHINGTON POST)

Sen. Mark R. Warner would have a far easier time winning the Virginia governor’s mansion next year over the all-but-declared Democrat and two Republicans officially in the race, according to a new Washington Post poll.

Warner (D) has been coy about any plans to run for governor, a post he held from 2002 to 2006. But he would start with a much stronger base of support than fellow Democrat Terry McAuliffe or Republicans Lt. Gov. Bill Bolling and Attorney General Ken Cuccinelli II, the poll finds.

Nearly three in 10 registered voters say they would definitely vote for Warner, and 22 percent would rule him out. Those numbers are starkly different from those of the three other hopefuls tested in the poll: McAuliffe (7 percent definitely for, 28 percent definitely against), Cuccinelli (12 percent for, 41 percent against) and Bolling (7 percent for, 30 percent against).

The results suggest that there is still room for Warner — or perhaps someone else — to step in and walk away with the race, despite the unusually early start that Republicans got on it.

Warner did nothing to snuff out talk of a comeback this month as he expressed frustration with his current job in an interview with The Washington Post. Asked whether he would quell rumors that he might run for governor, Warner said: “I’m not going to quell anything.”

Virginia law prevents governors from serving consecutive terms but does not preclude a return after a break.

Robert E. Brogan, a U.S. Department of Transportation safety analyst and Democrat who lives in Falls Church, said he would most likely support Warner because he was “successful once before as governor, he has progressive policies and a very balanced approach to things.”

A self-made millionaire and self-described “radical centrist,” Warner enjoyed a whopping 80 percent job approval rating in a Post poll just before leaving office as governor. More than six in 10 have approved of his work as senator since he took the job.

McAuliffe — a longtime friend of Bill and Hillary Rodham Clinton, former Democratic National Committee chairman and green-car businessman — has told supporters that he plans to run for governor but that he will not formally announce his intentions until after November.

Despite a high national profile, McAuliffe has not registered much support in Virginia, where in 2009 he lost his party’s nomination for governor to an unassuming state senator from rural Bath County, R. Creigh Deeds, who went on to lose to now-Gov. Robert F. McDonnell (R) by nearly 18 points.

Almost as many conservative Republicans say they would definitely vote for Warner (12 percent) as liberal Democrats say they’re sold on McAuliffe (16 percent). Among those liberal Democrats, 50 percent say Warner can count on them.

Bolling has been waiting to make a gubernatorial bid since stepping aside in 2009 to allow McDonnell to run unopposed. His part-time job as lieutenant governor put him in the spotlight more this year as he presided over an evenly divided state Senate. He cast a record 28 tie-breaking votes, tipping the balance on voter ID, ultrasound-before-abortion and other hot-button bills.

Even so, some voters have not taken notice of him.

Bob Williams, who works in computer security and leans Republican, said he knew nothing about Bolling.

“I remember hearing about Cuccinelli before,” said Williams, 38, of Orange.

By contrast, the combative Cuccinelli has grabbed national headlines by battling climate scientists, abortion clinics and “Obamacare.” He shook up the GOP race by announcing early this year that he would challenge Bolling for the party’s nomination.

The poll shows Cuccinelli has better name recognition among Republicans than Bolling, who has focused more on the economy than on social issues as McDonnell’s chief jobs-creation officer. A quarter of Republicans said they would definitely vote for Cuccinelli if he were the GOP nominee, compared with 15 percent for Bolling.

But Cuccinelli appears to be the weaker Republican among Virginians overall. Forty-one percent of all registered voters flatly rule out voting for him. Sixty-eight percent of Democrats say they would not even consider doing so.

Even among groups that would seem to be his base, Cuccinelli lacks rock-solid support. More than twice as many white Catholics say they’d definitely vote against him than definitely for him. Twenty-eight percent of white evangelicals are firmly opposed to Cuccinelli, while 19 percent are definitely behind him.

When it comes to the current governor, the poll finds that McDonnell’s approval rating remains in solidly positive territory; 58 percent of voters give him the thumbs-up. That’s unchanged from a Post poll conducted in May.

The poll was conducted by telephone Sept. 12-16 among a random sample of 1,104 adults in Virginia, including 934 registered voters. Interviews were conducted on conventional and cellular telephones and carried out in English and Spanish. The margin of error for results among registered voters is plus or minus four percentage points.

Scott Clement, Jon Cohen, Errin Haines and Ben Pershing contributed to this report.