Sen. Ted Cruz of Texas has opened up a 9-point lead on 2016 GOP rival Donald Trump in the early state of Iowa, according to a new poll that shows Mr. Cruz pulling support from former Ben Carson supporters.
Mr. Cruz was at 40 percent in the CBS News/YouGov poll, followed by Mr. Trump at 31 percent, Sen. Marco Rubio of Florida at 12 percent, and Mr. Carson, the retired neurosurgeon, at 6 percent.
In a CBS/YouGov survey released in late October, Mr. Trump and Mr. Carson had been tied at 27 percent apiece, with Mr. Cruz at 12 percent and Mr. Rubio at 9 percent. Last month, Mr. Trump had re-taken the lead at 30 percent, with Mr. Cruz at 21 percent, Mr. Carson at 19 percent and Mr. Rubio at 11 percent.
In the survey released this week, 47 percent of the Iowans who had supported Mr. Carson in November but switched their support went to Mr. Cruz and 37 percent went to Mr. Trump.
About six in 10 Iowa Republicans said national security and terrorism are most important to them in considering their vote, and Mr. Trump and Mr. Cruz were running about even there.
Of the one in five who said faith and religious values matter most, though, Mr. Cruz was leading Mr. Trump by more than five to one among those potential voters.
The survey was conducted from Dec. 13-17 by YouGov, an online polling organization, but included registered voters who were contacted by phone. Most respondents were recontacts, meaning most participated in the November wave of the poll.