ABC News contributor Cokie Roberts reports:

As the nation turns its eyes toward America's heartland today for the Iowa caucuses, there is one very important caveat to keep in mind when extrapolating the results of this first nominating contest: the Iowa caucuses are very, very strange events.

The media places enormous emphasis on the caucuses because the candidates do but, honestly, what happens in the Iowa caucuses is 100 people, at most, in many cases standing around somebody's living room and convincing each other to vote for a particular candidate.

It is Betty Sue coming over to Mary Jane and asking her to come to her candidate's corner, after all her home-baked brownies are in that corner. It is all about neighborly persuasion for personal reasons and predicting exactly how that kind of dynamic plays out is notoriously fraught with mistakes.

The Iowa caucuses are overhyped and, frankly, absurd, but we are all kind of stuck with them. While they are about as helpful as a coin toss at predicting who the eventual nominee will be, the results do make a big impact on candidates' momentum. And, in politics, momentum is money.

The real question tonight is what happens to Mitt Romney.

If the former Massachusetts governor can show that in the state in which he originally did not expect to do well, he has the organization and ability to appeal to Iowa Republican caucus-goers, it will be telling for his money and momentum going forward.

It is possible he can pull that off and take the top spot, but it is unlikely.

What is far more probable is that Iowa Republicans flock to Rick Santorum, who has surged into third place in the most recent Iowa polls, or Texas Rep. Ron Paul or even former House Speaker Newt Gingrich.

Not to brag, but six weeks ago I predicted Santorum would be the next candidate to rise in Iowa. After all, he has practically lived in the state for the past seven months and has some of the same socially conservative views as many Iowa Republican caucus-goers.

As Iowans, and conservative Republicans in general, search for a non-Romney candidate, I predict many of those voters will land in the Santorum camp. That doesn't necessarily mean the former Pennsylvania senator will come in first tonight, but he will do very well.

Bottom line, the top spot could easily go to Romney, Santorum or Paul, in any order.

Paul's enthusiastic supporters are sure to turn out in droves and employ their best brownie-inspired persuasion techniques on their neighbors.

Santorum, who has positioned himself as a personally committed and experienced "pro-lifer" in a state that is very "pro-life," is sure to draw support from die-hard social conservatives.

And Romney has the money, the electability and the poll numbers to make an impressive showing. The worst-case scenario for Romney tonight would be a third- or fourth-place finish.