So why doesn’t Mitt Romney advance any policy ideas, anyway? In particular, why doesn’t he advance some ideas — on the economy preferably, but any issue would do — to shield himself from the obvious attack that he’s a more-of-the-same return to the still-unpopular George W. Bush?

It's no surprise that he doesn’t want a lot of focus on his own proposals; as with most challengers, his best bet is to win all of the votes of people unhappy with the incumbent, and so being as much a generic opponent as possible is a logical strategy. But that doesn’t quite explain his frequent — and sometimes comical — refusal to have any policy positions at all on numerous issues. In particular, Barack Obama has already begun to attack him as a return to Bush; one would think that a few (bland, unthreatening) policy proposals could convince many in the press to at least not amplify that message.

So why doesn’t Romney differentiate himself from Bush? It’s pretty simple, and it gets back to what drives much of the Romney program: fear of conservatives. Or to put it another way: party constraints. After all, while most voters may think of Bush as a typical conservative Republican, many Tea Partiers and other conservative activists see Bush as one step (if that) removed from the dreaded RINO label. And so for Romney, who still must worry about keeping activists happy, there’s no way to square the circle. If Bush was dangerously moderate, then deviating even a bit to the center would put Romney in dangerous territory for activists. But of course a move to the right to separate himself from Bush, and Romney would be courting a reputation for extremism that could be trouble for him with swing voters.

Granted, Romney might have found ways of moving on to new issues that were perceived as neither left nor right. But that’s apparently not his strength as a politician, and it’s not as if the other Republican candidates, Ron Paul excepted, were generating interesting and untried policies of their own. At any rate it would have been too risky during the nomination process, given how easily conservatives have turned on seemingly (and formerly) safe conservative positions. Better, in the primaries, to use attitude (all that stuff about bowing and apologizing, for example) as a substitute for issues for appealing to conservatives.

And for general election swing voters, Romney is following the same path: substituting attitude such as a vague support for jobs for issues — and taking the hits from the occasional reporter who cares about such things — and hoping that it’s enough. It has a down side; it's getting him a reputation in the press for ducking issues, and it makes it easier to paint him as Mitt W. Romney — but given his constraints, it’s a rational strategy. Expect plenty more of it.