There’s an excellent chance that Mitt Romney will win the Iowa caucuses. He’s way ahead in New Hampshire. He could, that is, pull off a Daily Double that John McCain, George W. Bush, Bob Dole, George H.W. Bush and Ronald Reagan all failed to do. Does that mean that if he edges out Ron Paul, Rick Santorum and Rick Perry on Tuesday evening that he’s locked up the nomination? Ezra Klein, for example, says this morning, “The momentum coming out of the caucus can cement Romney as the nominee.” I don’t think so.

Now, Romney is in excellent shape, regardless of what happens in Iowa. He has far more support from party actors than any other candidate – far more than the rest of the field put together, in fact. Indeed, it’s very possible that he has the nomination locked up already, with big-gun endorsements in the bag, just waiting to be rolled out post-Iowa (perhaps being held to combat any post-Iowa trouble if Romney slumps to third or even fourth).  InTrade has Romney with about a 75 percent chance of being the GOP nominee right now, and, if anything, that’s probably low.

But the truth is that Romney still doesn’t have the endorsement profile that a dominant candidate could have at this point. So the question isn’t really whether Romney wins in Iowa; it’s whether those who haven’t supported him yet are just hesitant about him or actively opposed to him. It’s how those reluctant party actors feel about the alternative or alternatives who emerge out of Iowa.

And that means that this month really hasn’t been as good for Romney as the conventional wisdom (as measured, say, by InTrade) seems to believe. A Romney/Gingrich/Paul contest after Iowa? Well, we’ve seen how vulnerable Newt Gingrich was to attacks. No matter how reluctant party actors may be to accept Romney, very few of them would side with Gingrich if it came to that. Nor would they have sided with Michele Bachmann had she surged again (or, for that matter, with Herman Cain if he had stuck around and done well in Iowa).

But as of right now, it looks as if the post-Iowa contest will be Romney against either Rick Santorum or Rick Perry or both (with, to be sure, Ron Paul hanging in there for his relatively small percentage). Santorum and/or Perry will have 18 days to make their case in South Carolina; we’ve seen plenty of surges, based only on national media, happen more rapidly than that. If, say, Santorum finishes third behind Romney and Paul in Iowa, and if a large segment of the party really is anti-Romney and finds Santorum acceptable, then the former Pennsylvania senator is going to get hit with tons of money and attention, and he’ll have a fighting chance in South Carolina. Indeed, I wouldn’t be surprised at all if Iowa produces a serious surge for Santorum in New Hampshire.

In other words, if there are still questions about Romney, Iowa isn’t going to answer them, and his relatively home turf of New Hampshire certainly isn’t going to answer them. Again, one possibility is that there really aren’t questions about Romney, at least from most party actors. But if they’re not sold on him yet, I don’t see that Iowa (and New Hampshire) are going to do the trick.

The basic story: At least one candidate in addition to Ron Paul is going to fight on against Romney after Iowa. That candidate will not be deterred by a poor finish in New Hampshire. Romney is going to have to beat him or her in South Carolina to really show that it’s all over. And if there are a lot of party actors out there who would prefer Rick Santorum (or Rick Perry, if he can stay alive) to Romney, then South Carolina will be truly competitive. And the exact finish in Iowa won’t really change any of that very much.