On the very day I write a post about how smart Romney's campaign is, he goes and does this Donald business. Amazing. But...maybe I'm right after all, I'm thinking. So while everyone (else) in the media is saying what an idiot Romney is, consider this opposite case.
Just because Romney won the nomination doesn't mean the wingnuts love him. They're still in the process of making their peace with him. As such, he has to send them signals every once in a while. Hanging out with Trump is a pretty strong signal. Hits several key buttons, not the least of which is that it sends the media into apoplectic shock, which the right wing loves.
In fact, I would guess that that was the whole point as far as the Romney team was concerned. The birther stuff matters, of course, but it feeds into and becomes an anti-media narrative: The media have decided that Republicans can't talk about Obama's provenance, ergo doing so pisses them off, and that's great. On talk-radio all over the country today, they're going to be rising to Romney's and Trump's defense and making fun of Wolf Blitzer.
This isn't a stupid thing to do in late May. Stuff like this gets riskier after Labor Day, but by then, the Romney camp probably figures, the hard right will be worked up enough by Obama hatred that he won't have to do this sort of thing anymore. Which means, if he's still doing it then, we'll know he's in trouble.