So John McCain has apparently made his choice for running mate. And in contrast to the lead-up to Obama's selection of Joe Biden, the Republican field seems wider and filled with more uncertainty; there's a strong sense that Maverick McCain could pull a real shocker out of his hat. As we did last week in the leadup to the Democratic veep pick, let's throw out some odds on the names that have been in the rumor hopper:

Mitt Romney
Odds: 2-1

Romney brings a number of significant benefits to McCain's ticket. Least important, but not to be discounted, is the former Massachusetts governor's statesmanlike and telegenic appearance — with millions of HDTV-watching voters scoring this one on looks, Romney will nicely counterbalance the short, pale, pocked, waxy-skinned, and scowl-prone McCain. Beyond that, he brings executive experience, knowledge of economics (or a plausible claim to it, anyway), solid fiscal-conservative street cred and social-conservative street cred that's better than McCain's if still imperfect, and a private-sector, outside-the-Beltway freshness. Don't discount the mileage the ticket could wring out of that last point, against the done-nothing Obama and the career-politician Biden.

There's good reason to hope that Romney could put McCain over the top in several key states: Republican states now in jeopardy (Colorado and Nevada) and the battleground state of Michigan. Winning those three plus Ohio, Florida, and New Hampshire (where McCain is popular) would more than compensate for losing Pennsylvania, Iowa, the rest of the upper Midwest, and even Virginia.

BUT: McCain clearly doesn't like him personally, and every indication is that McCain's a man who lets emotions and gut feelings guide his decisions. Also, choosing the wealthy Romney would stoke the fires of Democratic class-warriors.

Tim Pawlenty
Odds: 5-1

Another affable governor, and one from a region where Republicans had been making gains but which now trends heavily Obama-ward. Dependably pro-life and a deficit hawk, Pawlenty also has base-pleasing positions on guns and border control, and appears to be something of a leader on energy issues. His humble background and unassuming personality, typical of so many in his region, would help mitigate Democratic charges that McCain is "out of touch". And if McCain likes him personally (as apparently he does), then the synergy on the ticket could pay dividends that exceed the sum of its parts. Finally: raised Catholic but now a member of an Evangelical church, Pawlenty might also appeal to the not-insignificant constituency of ex-Catholics...

BUT, Pawlenty has virtually no national profile. That, combined with his mildness, could depress the energy level on the ticket. There's also good reason to doubt that his presence would deliver Minnesota or Wisconsin.

Joe Lieberman
Odds 10-1

Choosing Lieberman — re-christened an Independent because of his support for the war but a Democrat in every other way that counts — would signal definitively that McCain aims to discard the Republican playbook of the last three decades, building a coalition that replaces social conservatives with hawkish moderates and disaffected Clinton supporters. It's a gamble that many predict would destroy the Republican Party, and reports suggest that McCain's advisors are begging him to let it go. But McCain — who, let's remember, was himself widely rumored to have been a serious candidate for John Kerry's running mate in 2004 — has seemed unwilling to rule it out.

A Lieberman choice would be fascinating, first because it would reveal whether a Republican really could succeed after abandoning his base; that is, whether such a new coalition would be viable. If so, it would change national politics forever. Secondly, because it would provide the signal for which many social conservatives have been waiting — itchy to desert a party they feel has given them more promises than results.

Tom Ridge
Odds: 15-1

Mr. Homeland Security is still popular in Pennsylvania, where he served as governor, and like Lieberman he's a close confidant of McCain's. Also, like Lieberman, he's no social conservative, and his selection would probably produce three-quarters the revolt that Lieberman's would. Apart from the Pennsylvania connection, this would be another pick that puts gut feelings above conventional strategy.

Sarah Palin or Kay Bailey-Hutchinson
Odds: 40-1

I think pundits who predict that a female choice for the VP slot would help win Clinton supporters mis-judge their motives; they want Hillary, not just any candidate with a pantsuit and an extra X chromosome. Likewise, I think some have exaggerated the value of matching Obama with another "novelty" candidate. Of these two, Palin is especially appealing to conservatives, but at 44 and only two years into her term as Alaska governor, her time hasn't come yet.

Bobby Jindal
Odds: 40-1

See "Palin, Sarah" above. A five-tool conservative all-star with an ethnic backstory that matches Obama's, there's no question that Jindal is going places. But the time isn't right — not this election year. He has work to do in Louisiana, and he knows it.

Dark Horse/Unknown
Odds 100-1

In this category would go your Brownbacks, Thunes, Bracegirdles, and assorted congressmen and Republicans-at-large. It's almost unthinkable that McCain would pick someone who hadn't been leaked and vetted by public opinion, but you never quite know what the Maverick will do.

Hillary Clinton
Odds: 10,000-1

"Political pornography," one talk-radio host called the thought of a McCain-Clinton ticket. And indeed it would turn the party system as we know it upside down. The odds grew tenfold longer after Hillary's convention speech, but it's still not so incredible as to be outside the realm of possibility. Such a choice would signify a playbook-scrapping to the nth degree. And the scary thing? Such a ticket just might win.