As the aura of inevitability around Mitt Romney grows and as attacks on his record appear more frivolous, more and more potential voters see the former Massachusetts governor as an “acceptable” nominee, according to a Gallup poll released today.

Fifty-nine percent of self-identified conservative Republicans say they find Romney acceptable, as do 59 percent of self-identified moderate or liberal Republicans. That makes Romney the only candidate with majority support among both the conservative and liberal wings of the GOP, as Gallup explains:

Romney’s broad acceptability across ideological lines is decidedly not the case for his competitors. Conservative Republicans view Gingrich, Santorum, and Perry as more acceptable than do moderate/liberal Republicans. On the other hand, moderate/liberal Republicans on average view Paul and Huntsman as more acceptable than conservatives.

Nevertheless, the race remains fluid. Little more than a month ago, 62 percent of Republicans and Republican-leaning independents considered Newt Gingrich an acceptable nominee; now, just 46 percent do. Inversely, just 27 percent of Rs and GOP-leaning indies considered Santorum an acceptable nominee a month ago; now, 45 percent do.

Romney will likely win tonight in New Hampshire, but that doesn’t mean the race is over. So far, he has managed to run a surprisingly impeccable campaign — just a few gaffes to his name — but he’s far from infallible. He’s still capable of uttering comments that aren’t particularly vote-savvy, even if they make sense. The ongoing flap about his “firing” comments are proof of that. Perhaps most importantly, he has yet to generate the kind of enthusiasm that Republicans presumably would like to feel about their nominee. Even in New Hampshire, where Romney is highly favored to win, his numbers have dropped as other candidates have put in appearances in the state. The Fix’s Chris Cillizza even suggests that, if Romney fails to win the Granite State with a double-digit victory, his win could be painted as an underperformance. Should the other GOP candidates ever decide to attack him for the legitimate flaws in his record and should conservatives decide to coalesce around a different candidate, the GOP primary picture could be very different coming out of South Carolina than it is going into New Hampshire.

Then again, if the old article of faith is right that, when it comes to primaries, “Democrats fall in love, while Republicans fall in line,” then Mitt Romney will probably be the nominee.