If rumors are to be believed, Mitt Romney is somewhere near the top of McCain's list. But given what the McCain campaign is now doing to the Obama-Biden ticket, will it stay that way?

The McCain campaign has a good thing going attacking Obama's inexperience using Biden's own words. It probably won't change the election, but it's a good line of attack. Of course if McCain hits up Romney, the campaign will effectively lose that tactic. Or at least the Obama campaign will be able to blight those attacks by running Romney videos attacking McCain.

It would be a different line of attack obviously. Romney didn't say McCain wasn't experienced enough to be president. He just said -- over and over again -- that McCain was too liberal for Republicans. Still, it's the running mate bashing the nominee.

Which might not be enough to keep McCain from choosing Romney and reaping the net benefit in a key state like Michigan. What it may do is bring both lines of attack to an end, as the media eventually agrees that it's pretty pointless.