A decade past his glory days as the nation's first elected black governor, Doug Wilder will turn 75 by the time Virginia's next governor is inaugurated in January. Spry, twinkly, his hair an elegant puff of powdery white, Wilder, now mayor of Richmond, is old enough to have attended segregated schools, fought in the Korean War and graduated from college when Truman was president.

But even now, the man's definitely got game. And the game now, as always, is: What's Doug going to do?

Go ahead and ask him: Will he or won't he endorse Lt. Gov. Tim Kaine for governor? Or for that matter, former attorney general Jerry Kilgore? Will he endorse at all?

"Probably so but maybe not," says Wilder, leaning back from his desk at Richmond City Hall. "But as I say, probably so."

Those probablys and maybes must be driving Kaine nuts, for Wilder's active support is among the pieces that must fall into place if he is to offset Kilgore's natural edge in Republican-leaning Virginia. Unlike Kilgore, Kaine has a margin of error in this campaign of precisely zero. He could win without Wilder's backing, but in a tight race -- and this race may be tight -- it would be harder.

Democrats do get elected in Virginia, but only by busting the party's liberal, free-spending stereotype. Wilder and incumbent Gov. Mark Warner are the two mold-breaking Democrats whose imprimaturs would confer centrist respectability -- and electability -- on Kaine. Both managed to blur the partisan divide and position themselves as independent-minded enough to appeal to moderate Republicans; both have maintained prestige and popularity despite the state's Republican tilt.

Warner, who is laying plans for a possible presidential race, hosted a $1 million fundraiser for Kaine at Tysons Corner last month, and he gives every sign that he'll work hard to get him elected. But Wilder is a wild card. No one can predict what he will do -- which is just the way he likes it.

Kaine, he allows, is a "more polished and more direct" candidate than Kilgore, whose record as attorney general he rates as "on average . . . acceptable." Then he hastens to add: "And you can say the same thing about Kaine" as lieutenant governor.

Conventional wisdom on Wilder says that he is purely self-interested and allergic to lasting alliances. That's part of what makes him so unpredictable. Most politicians of his vintage would plaster offices with photos of themselves in the company of presidents, prime ministers and other luminaries. Not Wilder: The photos and framed clippings on his walls star none other than . . . Doug Wilder.

The constant of his career has been his flair for improvisation and political theater, and for inserting himself in the starring, often melodramatic, role. Lately his stage has been city hall, where he was installed early this year after winning 80 percent of the vote in Richmond's first city-wide mayoral election in 60 years. After that coronation, some expected that Wilder would govern as a benign septuagenarian, ruffling few feathers; after all, practically everyone was already on his side.

Fat chance. This spring Wilder instigated a bitter brawl with the city council over the budget, picking fights along the way with some of Richmond's leading business groups, nonprofits, advocates for a proposed downtown performing arts center and the Richmond city attorney. He also hired his nephew onto the city payroll, further antagonizing a growing list of critics.

It was, of course, just a dose of Wilder's trademark panache -- his way of shaking up the scene and signaling Richmond, which he says needs wholesale change, to expect the unexpected. But the drama also contained the seeds of embarrassment for Kaine. After all, if Richmond is, as Wilder said when he ran for mayor, a "cesspool of corruption and inefficiency," what does that say about Kaine, who was Richmond's mayor -- albeit a largely ceremonial one -- before he became lieutenant governor?

In 1997 Wilder sat on his hands when Don Beyer was the Democratic candidate for governor, angering party loyalists; Beyer was trounced. But when Warner ran in 2001, Wilder, then in semi-retirement, was an important asset, not only endorsing him but, as he puts it, "getting around the state and pumping and moving."

Kaine's a different story, and he and Wilder are an odd couple. Kaine opposes the death penalty, which Wilder supports. Kaine's a moralist and a policy wonk who can be politically tone-deaf. Wilder, oozing charm, is a pol's pol, with some of the sharpest antennae in the game. It's a little harder to imagine Wilder "pumping and moving" for Kaine.

The electoral key for Virginia Democrats is winning over moderate Republicans and other swing voters. And it is precisely that voting bloc that Wilder, with his credentials as a fiscally conservative, independent-leaning Democrat, could influence. "The swing voter is out there," he says. "I identify with the swing voter and they identify with me because I don't allow party affiliation to dictate what I do."

All of which leaves Kaine to squirm and wonder: What's Doug going to do?

The writer is a member of the editorial page staff. His e-mail address is hockstaderl@washpost.com.