Could the race in Iowa really go to a man who has spent the least amount of time in the state among all of the candidates vying for caucus-goers?  Rasmussen’s latest poll of 750 likely caucus-goers show Romney with a small but statistically significant lead, 25% to 20% for new second-place candidate Ron Paul.  But the big move may be from the second tier:

Former Massachusetts Governor Mitt Romney and Texas Congressman Ron Paul are leading the pack in Iowa with just two weeks to go until Caucus Day. But large numbers of voters remain uncommitted and lots could change between now and January 3.

The new Rasmussen Reports survey of Iowa caucus participants shows Romney on top with 25% of the vote followed by Paul at 20% and former House Speaker Newt Gingrich at 17%. Texas Governor Rick Perry and former Pennsylvania Senator Rick Santorum, both at 10%, are the only other candidates in double-digits.  Minnesota Congresswoman Michele Bachmann earns six percent (6%), former Utah Governor Jon Huntsman four percent (4%), while one percent (1%) prefer some other candidate and eight percent (8%) are not sure.  …

This poll reflects the highest level of support yet measured for Romney and Paul. It’s also by far the best result yet for Santorum who on Tuesday received an endorsement from Bob Vander Plaats, a major social conservative leader in Iowa. While the Evangelical Christian vote is very divided at this time, Santorum now picks up 19% of it, more than any other candidate. Romney is close behind at 18%.

Among those who say they are certain to participate in the caucus, Romney and Paul are essentially even. As always in a caucus, the organizational effort to get identified supporters to show up on January 3 is likely to determine the outcome.

The organizational edge might go to Paul — but it might not, either.  Even if Romney has not spent much time in Iowa, he has built a significant organization in the state, and he launched a massive ad buy of over $3 million last week.  Furthermore, Romney isn’t having to compete against expectations, so a big finish here might be enough to generate enough momentum to run the table in the early states — especially if Paul ends up being the second-place finisher.  A Gingrich third-place finish would put a serious dent  in his credibility as a candidate.

And it might get worse than that.  Both Perry and Santorum have moved up to 10% in this poll, but Santorum’s support is almost double that of a week ago.  Bachmann has not gotten the same kind of boost, remaining at 6%.  Santorum edges ahead of Perry among Republicans (13% to 11%) and just behind Paul’s 14%, but both trail Romney (27%) and Gingrich (21%).  Paul gets 32% of independents, which is no great shock, and Romney comes in second at 19%, which is also no great shock.  Among those who consider themselves “very conservative,” Santorum comes in third at 19%, almost tying Gingrich and Romney, who get 21% each. Santorum now also comes in third among Tea Party adherents at 17%, just behind Romney at 18% and Gingrich at 23%, and ahead of Paul (14%) and Perry (12%).

As for Paul, this poll shows that his bounce is real, if sometimes overestimated, but he has significant issues in this support.  When asked to pick the weakest candidate to put against Obama, Paul wins with 26% of the respondents, followed by Michele Bachmann at 21% and Gingrich at 16% — a danger sign for Gingrich as well.  (Santorum only gets 4%, but then again, he only gets 4% in the question on which candidate would be strongest, too.)  Gingrich does well in the strongest-candidate question with a second place 25%, but that’s ten points below Romney’s 35%.  Paul only gets 15% on this question, making him the only one of the top three to underperform his support on this question.  If caucus-goers break late on the question of electability — and it’s certainly a trend we’ve seen in the past — then Romney stands the most to gain.

A third-place finish would be a boost to Santorum, who hasn’t ever broken out of the pack, and a big disappointment to Gingrich, who had a big lead in Iowa just a couple of weeks ago.  If Paul falters, Romney will probably get the most benefit, but Santorum could be riding a wave that could crest with perhaps even a second-place finish, if social conservatives in Iowa begin to flock to his banner — and that could have South Carolina Republicans, known for their evangelical social conservatism, taking a new look at Santorum.  We’ll see.