Either Barack Obama or John McCain may pick a running mate this week, before the Olympics start.

I haven’t heard much buzz lately about McCain’s choice. My money’s still on Mitt Romney, who has a relatively coherent message on economic policy (for a Republican) and can raise a lot of cash.

Word is that Hillary Clinton will address the Democratic National Convention in Denver on the Tuesday night. Since Obama’s running mate is expected to speak on Wednesday night, it seems that Hillary is not under serious consideration for VP.

Matt Stoller is still pushing for Wes Clark, and he and other bloggers have started a draft Clark for VP site, but I see no evidence that Clark is even being vetted by Obama’s team. They seem to want to avoid picking someone who will be seen as “balancing” any weakness in Obama’s resume.

Todd Beeton suspects the Obama team has decided the running mate should have some Washington experience, and he made a fascinating observation at MyDD:

My gut tells me a couple of things. First of all, Barack is not going to pick someone who needs to be introduced to the country. He has enough of an uphill climb introducing himself to the nation, is he really going to pick another unknown quantity for the ticket? So that leaves us with a different list, which, let’s say for argument, looks like this: Hillary Clinton, John Edwards, Wesley Clark, Joe Biden, Bill Richardson, Chris Dodd, Sam Nunn.

Among these possible picks, some are known thanks to their extensive Washington, DC resumes (Clinton, Biden, Nunn, Dodd), some are not (Clark, Edwards, Richardson.) So, which list will Obama pick from? You’ll recall that in the primary, Barack ran against Washington experience and turned what Hillary thought would be her top selling point into an albatross around her neck with one very effective line: “are we just going to keep sending the same people to Washington and expect a different result?” In other words, if you’ve spent a lot of time in DC then how can you expect to change it? He could and should be using the same line against McCain, but he’s not. The other day I noticed him almost say it at one of his townhalls, but he caught himself. Why? My gut is that he’s leaning toward picking a Washington insider for his VP. My guess is it’s Biden.

Biden wouldn’t be my first choice for VP, but he would be a good fit for Obama in many ways. He’s a strong campaigner and could be an effective attack dog. Also, I think he would help Obama with the over-60 voters, where he is relatively weak.

Then again, First Read reports that the press team following Obama will spend 21 hours in South Bend, Indiana from Tuesday evening to Wednesday afternoon. They suspect that Obama might select Indiana Senator Evan Bayh as his running mate there.

Like Biden, Bayh is a Washington insider, but he’s also a former governor of a red state. He endorsed Hillary Clinton for president, so that might be a gesture toward uniting the party.

Then again, Obama may just be planning to hold a few campaign events in Indiana because that state could be competitive this year.

Bayh is way too conservative for my taste; for instance, he voted for Bush’s tax cuts in 2001. More worrying, we would likely lose his Senate seat if he became vice president, unless Jill Long Thompson pulls off an upset in the Indiana gubernatorial race this year. If Obama wants a Washington insider, I’d prefer Biden.

Many people still expect Obama to choose a different red state governor, either Kathleen Sebelius of Kansas or Tim Kaine of Virginia.

For whatever reason, New Mexico Governor Bill Richardson doesn’t seem to be on Obama’s short list. That’s too bad, because I like him a lot more than Kaine, and I think he brings more to the table than Sebelius.