(WSLS 10) -Â Donald Trump and Texas Sen. Ted Cruz are locking in their lead among Iowa likely Republican Caucus participants, with Trump at 31 percent and Cruz at 29 percent, while U.S. Sen. Marco Rubio of Florida trails with 15 percent, according to a Quinnipiac University poll released Monday.
Dr. Ben Carson has 7 percent, with no other candidate above New Jersey Gov. Christopher Christie's 4 percent.
Recommended Videos
This compares to the results of a December 14 survey by the independent Quinnipiac University showing Trump at 28 percent, with 27 percent for Cruz, 14 percent for Rubio and 10 percent for Carson.
Today, 5 percent are undecided, but 46 percent of those who name a candidate say they might change their mind.
Trump tops Cruz almost 4-1 on the negative list as 26 percent of Iowa Republican Caucus-goers say they "would definitely not support" Trump, with 7 percent who would not support Cruz.
The biggest loser today is former Florida Gov. Jeb Bush, who gets only 3 percent support from Republicans, while 26 percent say they "would definitely not support" him.
The economy and jobs is the most important issue for 27 percent of Iowa likely Republican Caucus participants in deciding their vote, as 18 percent list terrorism; 16 percent say foreign policy. Another 10 percent cite the federal deficit and 8 percent list immigration.
This reverses the results of the December 14 survey, in which 30 percent listed terrorism as the most important issue, with 21 percent focused on the economy and jobs.
Trump can best handle the economy, 46 percent of Republicans say, with 16 percent picking Cruz and 8 percent picking Rubio. Trump is also best handling terrorism, 36 percent of GOP Caucus participants say, with 26 percent for Cruz and 12 percent for Rubio.
Cruz is best on foreign policy, 27 percent of Republicans say, with 24 percent for Trump and 18 percent for Rubio. Trump is best on illegal immigration, 46 percent of GOP Caucus-goers say, with 22 percent for Cruz and 15 percent for Rubio.
Cruz has a 75 – 17 percent favorability rating, with Trump at 61 – 34 percent.