As we discussed a few months ago, some polls matter more than others. In Iowa, the Des Moines Register‘s Iowa Poll is widely considered the gold standard for Hawkeye State polling, and therefore gets considerably more attention than other surveys in the state.

And with that in mind, and the caucuses just a few days, here’s what the race for the Republican presidential nomination looks like in Iowa:

1. Mitt Romney: 24% (up seven points since early December)
2. Ron Paul: 22% (up four points)
3. Rick Santorum: 15% (up nine points)
4. Newt Gingrich: 12% (down 13 points)
5. Rick Perry: 11% (up five points)
6. Michele Bachmann: 7% (down one point)

Jon Huntsman, who was at 2% a month ago, was not mentioned in the Register‘s report this evening.

The results, however, come with a very important caveat: the Iowa Poll was conducted Tuesday through Friday, and the results from the first two days were quite different from the last two days.

[T]he four-day results don’t reflect just how quickly momentum is shifting in a race that has remained highly fluid for months. If the final two days of polling are considered separately, Santorum rises to second place, with 21 percent, pushing Paul to third, at 18 percent. Romney remains the same, at 24 percent.

“Momentum’s name is Rick Santorum,” said the Register’s pollster, J. Ann Selzer.

A couple of other tidbits jump out from the results. Perry, who insists he has a great ground game in Iowa, appears to have recovered from his free fall and has seen his support nearly double over the last month. Paul’s 22%, meanwhile, is the best he’s done in an Iowa poll so far this year, as is Romney’s 24%.

But the real story here appears to be the sharp increase in Santorum’s support in the contest’s closing days. Note: the best the former senator has done in a DMR poll this year is 6%. Now, at least over the last couple of days, Santorum is at 21%.

Best of all, there are still two days of campaigning to go, and 41% of likely caucusgoers “say they could still be persuaded to change their minds.”

Update: Here’s some additional analysis of where things stand in Iowa, including a look at Romney’s underwhelming frontrunner status, and the possibility of Santorum benefiting from a self-fulfilling prophecy.

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Steve Benen

Follow Steve on Twitter @stevebenen. Steve Benen is a producer at MSNBC's The Rachel Maddow Show. He was the principal contributor to the Washington Monthly's Political Animal blog from August 2008 until January 2012.