Last night’s Republican presidential debate provided pretty solid evidence for the theory that the other candidates have a special dislike for former Massachusetts Gov. Mitt Romney. All of them except Ron Paul got off some kind of a crack about Romney essentially being an opportunist or flip-flopper. And Romney didn’t help matters by merely grimacing at each joke and failing to come up with a comeback; he signaled early on that there was little risk in attacking him. (See a wrap-up of the debate here.)

It struck me after the debate that Romney simply hasn’t had a lot of experience engaging with political opponents — and therefore may not fit in with politicians who believe that, whatever happens during a debate, the participants should shake hands and put aside their differences at the end of the day. Romney has been a CEO and the head of the Olympics, and being governor of Massachusetts should have provided him with some experience at collegiality and “go along, get along” politics. But that didn’t seem to happen much during his term as governor, perhaps because of his own personality but also, certainly, because of an overwhelmingly Democratic legislature with a leadership strong enough to discourage individual members from crossing over to cooperate with Romney. The Legislature tended to simply ignore him except when overriding his vetoes (which they did, hundreds of times).

The one great exception to this lack of cooperation, of course, was the universal health insurance law that Romney proposed, and the Legislature passed, late in his term. But Romney didn’t exactly embrace the spirit of bipartisanship, vetoing provisions of the law (which the Legislature naturally put back) in what some took as an attempt to distance himself from it in case it didn’t work out. And as a presidential candidate, he doesn’t exactly brag about working with Ted Kennedy and other Democrats in Massachusetts in pushing the legislation through — in contrast to Democratic candidate Barack Obama’s frequent mentions of working with Republicans in the Illinois legislature and in Congress.

Among Romney’s Republican opponents, John McCain and Fred Thompson have served in the US Senate, where even a single member of the minority party can sometimes gum up the works through parliamentary procedure. Former New York mayor Rudy Giuliani, despite his autocratic reputation, did have to work with Democratic lawmakers at the state and federal levels (and, for part of his term, with Democratic Gov. Mario Cuomo) in the never-ending quest to get financial assistance for his city. And former Arkansas Gov. Mike Huckabee seems to have been more active in working with an overwhelmingly Democratic Legislature in that state. Opponents are now circulating a video of a speech in which Huckabee addresses the legislature and ticks off a list of possible tax increases that he would “gladly sign” if passed by Democratic lawmakers.  “You will have nothing but my profound thanks,” he tells them, implying that he’s willing to share the political heat with them in order come up with a solution to the state’s fiscal problems.

It’s tough to imagine Romney humbling himself to make a speech like that to the Massachusetts Legislature. Then again, it’s tough to imagine that the Legislature, which long ago stopped feeling any pressure to work with the opposition party, would have had a generous response. Either way, Romney’s fairly lonely term as Massachusetts governor may put him on a different wavelength from the other Republican candidates, who have had to swallow their pride and work with opponents through most of their political careers.