A plurality of 36 percent of tea party supporters also backed Sen. Ted Cruz. | AP Photo Poll: Cruz surges to first in Iowa

Stoked by evangelical and tea-party support, Ted Cruz has surged to first place in Iowa, according to the results of a Monmouth University poll released Monday surveying voters likely to participate in the Republican caucus on Feb. 1.

Cruz earned 24 percent of support among likely caucus-goers, with 19 percent opting for Donald Trump, whose polling advantage in the state has dwindled in recent weeks. In a Quinnipiac University survey conducted in mid-November, Trump held a slim 25 percent to 23 percent advantage over Cruz, while retired neurosurgeon Ben Carson finished with 18 percent.


In this survey, Florida Sen. Marco Rubio finished third with 17 percent, followed by 13 percent for Carson (a 19-point drop from October), 6 percent for former Florida Gov. Jeb Bush, 4 percent for Kentucky Sen. Rand Paul, 3 percent for former Hewlett-Packard CEO Carly Fiorina and 2 percent for New Jersey Gov. Chris Christie and former Arkansas Gov. Mike Huckabee. All other candidates finished with 1 percent or less support, with 4 percent undecided and 1 percent describing themselves as "uncommitted."

Cruz's advantage comes largely at the expense of Carson, who less than two months ago led the state's Monmouth poll by a 14-point margin over Trump.

This time, Texas senator commanded pluralities from evangelicals, with 30 percent supporting him, and 18 percent going for Trump. In October, Carson held a 36 percent to 18 percent advantage over Trump among that group. Cruz earned just 12 percent from evangelicals in the October Monmouth survey.

A plurality of 36 percent of tea party supporters also backed Cruz, with 20 percent for Trump, 17 percent for Carson and 11 percent for Rubio. Along gender lines, however, men prefer Cruz (29 percent) and Trump (24 percent) over Rubio and Carson (both at 12 percent). Among women, however, Rubio (23 percent) and Carson (19 percent) lead the way.

In terms of favorability, Cruz tied with Carson for the second-highest net-positive rating of 46 points (67 percent favorable to 19 percent unfavorable), while Rubio led with a net-positive rating of 54 points (70 percent to 16 percent). Elsewhere, Bush had a negative rating of 38 percent to 45 percent, while Trump earned a positive 18-point rating (54 percent to 36 percent).

With a little less than two months to go until the caucus, just 20 percent said they are completely decided on their choice, while 49 percent said they had a strong preference. Meanwhile, 18 percent said they had a slight preference, and 13 percent said they were undecided.

Nearly one in five likely caucus-goers said that Iowa Rep. Steve King's recent endorsement of Cruz made it a little or a lot more likely that they would caucus for him, but 73 percent said it would have no impact.

The poll was conducted Dec. 3-6, surveying via landlines and cellphones 425 registered voters who voted in at least one of the last two state primary elections, voted in both the 2012 and 2014 general elections or who have registered to vote in the past year. The margin of error is plus or minus 4.8 percentage points.