In a few hours, we should all start feasting on the results of the first real honest-to-gosh voting in the country, from the Iowa Caucuses. (At least us political junkies will be feasting.)

The RealClearPolitics national poll of polls isn’t very up-to-date at this point, since it has only one poll of six that includes any results after 12/18. That’s actually no big loss, since from this point on individual state results are what matter. Here’s what the much more up-to-date Iowa polling average is showing:

As you can see, Romney is currently eking out an extremely narrow lead over Ron Paul, and Rick Santorum is in the midst of a surprising last-minute surge that has him at third and rising. Poor Newt, who only a few weeks again was strongly leading, is now fourth.

These rankings may indeed hold, but, as my new friend Swing State Voter reminds us, a caucus is not like a primary. In short, it doesn’t depend on simple votes by secret ballot, but on committed voters showing up to very small meetings throughout the state, and publicly standing up for a candidate and convincing their neighbors to do so as well. This tends to favor candidates with the funding to organize and turn people out statewide (in this case Romney, and, though the polls don’t show it, Perry), or with a devoted following who will show up no matter what (Ron Paul to a T, and whoever the Evangelical vote most strongly backs, which seems at this point to be Santorum).

Absent from this list? Newt Gingrich, which could be very bad news for him.

It’s hard to see how a fourth place finish in Iowa wouldn’t result in a third or worse in New Hampshire, which would rapidly erode his position of strength in South Carolina and Florida later this month. Of course, as many analysts have pointed out, including Nate Silver at FiveThirtyEight.com, how you do relative to expectations actually ends up mattering more than where you place. If enough people think that Gingrich is a goner, and he then does better than expected in Iowa or New Hampshire, he could still remain viable. You may recall how in 1992 a cat named William Jefferson Clinton got blown out in Iowa and then placed second in New Hampshire, but compared to the DOA he was believed to be at that point, was actually able to spin that as a victory. Still, I wouldn’t advise Newt to hold his breath on pulling that off.

What about Romney? A win, even a narrow one, in Iowa, followed by almost certain victory in New Hampshire could turn this back into the quick coronation he’s wanted it to be all along. The only other candidates who were not sitting presidents that I could find who pulled this double-header off in the post-Watergate era were Al Gore in 2000 (who won 50 out of 50 primaries and caucuses) and John Kerry (who won 46 out of 50). But…

As Swing State has also pointed out, Santorum is the only person in that list who’s showing surging momentum, and as I’ve noted above, caucus dynamics favor “devotional” candidates like Ron Paul. Romney could just as easily end up third (even if very, very narrowly). He’d probably still win New Hampshire, but the fact that three other candidates there are sitting on double digits would be harder to spin away. The field would remain plenty feisty into Super Tuesday. And that field, which has concentrated on tearing each other down instead of targeting Romney in Iowa, could now start to spend against him heavily.

So it may not be quite over yet (before it’s begun!). Tune in in a few hours…