By Scott Conroy - January 1, 2012

DES MOINES, Iowa -- Mitt Romney leads the Republican field in the Des Moines Register's final pre-Iowa caucuses poll released Saturday night.

The Register's highly anticipated survey, which was accurate in predicting both the Democratic and Republican caucus winners in 2008, shows Romney holding the support of 24 percent of respondents. Ron Paul is in second place at 22 percent, while Rick Santorum has ascended into third with 15 percent.

However, Santorum appears to have all of the late momentum on his side, having surged significantly in the final two days of the four-day polling period. If considered separately, he is at 21 percent in that period, while Romney remained atop the pack at 24 percent during the second half of the poll’s sample.

A whopping 41 percent of likely Republican caucus-goers said they are open to changing their minds.

There may be just three days to go before Iowans head to their caucuses, but that is more than enough time to see dramatic changes in a GOP nominating fight that has shifted often and seemingly by the hour.

Perhaps the last significant wild card before Tuesday is the potential endorsement of Iowa Rep. Steve King, who told RealClearPolitics in an interview just hours before the Register’s poll was released that there was about a 50/50 chance he would get behind a candidate at the last minute.

“With big decisions, at some point your intellect is overcome by your instincts -- at least mine is,” King said. “If I make a bold decision in the next few days, it will be one of conviction, and I will be eager to advocate for that position and defend it against all critics, if I happen to have any, and I’m sure I will.”

The endorsement of King, perhaps Iowa’s most influential conservative voice, has for months been heavily sought by the Republican candidates.

Until recently, the five-term congressman has hinted that he was unlikely to back anyone publicly, but he suggested to RCP on Saturday that he may change his mind given the recent polling gains by Ron Paul, whose foreign policy King said is “so alarming to me.”

Just before the Register poll was released, King gave his sense of where the Iowa horse race stands.

“If I had to pick them, I’d say this: Romney, Santorum, Paul, in that order -- then I think likely Gingrich,” he said. “I do think Romney’s strong enough to win here in Iowa, and I do think Paul’s support is drifting away from him -- people are coming to grips with what that would really mean. And the third component of this is the ascendancy of Rick Santorum. Is his ascendancy a sharp enough incline to catch up with Ron Paul and Mitt Romney?”

King said that the final poll conducted by Iowa’s largest newspaper “would be a factor” in his decision, since he wanted to get behind someone who had discernible momentum.

In 2008, King endorsed Fred Thompson, whose campaign quickly fizzled after he finished third in the Hawkeye State.