Lee Hockstader
Exit Jim Webb; enter . . . who?

Jim Webb's announcement that he's quitting the Senate after his term is finished in 2012 confirms his refreshing reputation as a maverick unwed to the perks of office. It also cues the handicappers thrilled at the prospect of a toss-up open seat in a solidly purple state.

The immediate speculation is that Webb's departure clears the way for former Virginia governor Tim Kaine, who's been solid but miscast as chairman of the Democratic National Committee, to grab the party's nomination if he wants it.

Kaine's a perfectly plausible candidate - whip-smart, fast on his feet, energetic and almost universally recognized by Virginians. Still, he'll have to contend with his lack of a signature achievement as governor (thanks largely to Republicans who blocked his transportation initiatives) and, potentially more damaging, his deep personal and political devotion to President Obama, who handpicked him for the DNC post.

Remember, Kaine was among the first Democratic governors to back Obama for the party nomination, and the two remain close. In fact, at this point, Kaine and Obama are so tightly joined at the hip that it's difficult to imagine one winning and the other losing Virginia next year. And the president has lost ground in the state since he beat John McCain there in 2008. If he runs for Senate, Kaine will be defending not only his record as governor but also defending Obama's in the White House more than virtually any incumbent save Obama himself. That may be heavy baggage in Virginia.

Still, who could knock off Kaine should he seek the nomination?

The Democrats, whose winning streak in Virginia suddenly ran out of steam at the turn of the decade, have a surprisingly thin bench. Conceivably, Terry McAuliffe, who failed to get the party nomination for governor in 2009, could mount a campaign. So could, in theory, substantive but obscure figures such as former state lawmaker and transportation secretary Whitt Clement, who's been floated lately as a possible 2013 gubernatorial candidate. Both would have a lot of ground to cover between here and plausibility.

Then there's George Allen, whom Webb beat - strike that - who beat himself in his race for reelection to the Senate in 2006. Allen will never live down his macaca notoriety; I'll lay bets that it will feature in the lead - probably the headline - of most of his obituaries. But he retains some goodwill among Republicans who prefer to remember him as a conservative governor who notched some achievements in office than as a do-nothing senator whose swagger, arrogance and, many believe, oblique racism contributed to his party's loss of control of the U.S. Senate.

Allen would be tough to beat for the Republican nomination. But there are already rumblings that he will face opposition from a Tea Party candidate or others on the right, such as nativist demagogue Corey Stewart,√ chairman of Prince William County's Board of Supervisors.√ My guess is that Kaine, by contrast, would have a relatively clear shot at the Democratic nomination. Now that would be something new: The Democrats linking hands while Republicans bloody themselves in fratricidal battle.