A Reuters poll released Friday finds that GOP presidential front-runner Donald Trump has dropped 12 points in less than a week, his largest single poll-to-poll drop since he took the primary lead in July.

Trump was still the favorite among 31 percent of Republicans in a rolling Reuters/Ipsos poll conducted from Nov. 23 to Nov. 27, but down from 43 percent support registered on Nov. 22.

The downtrend comes after a week of controversial comments he made about Muslims living in America, suggesting he would “surveil” mosques to root out domestic terrorist plots.

He also suggested a registered database for U.S. Muslims, which drew comparisons to Nazi Germany’s mandatory registration of Jews.
Retired neurosurgeon Ben Carson also fell but finished second in the poll with 15 percent support.

Sens. Ted Cruz (R-Texas) and Marco Rubio (R-Fla.) tie for third with 8 percent support each. Former Florida Governor Jeb Bush comes in fifth with 7 percent support.

The five-day rolling average sample ranged from 464 to 347 online respondents and has a credibility interval of 5.2 to 6.1 percentage points.