Ted Cruz has replaced Ben Carson as Donald Trump's leading opponent for the Republican presidential nomination, a new NBC News/Wall Street Journal poll shows.
The survey released Sunday has Trump as the GOP front-runner with 27% support among likely Republican primary voters nationwide.
Cruz, the Texas senator, is in second place at 22% support, while Florida Sen. Marco Rubio is third at 15%. Carson is fourth with 11% backing.
It's a huge drop for Carson, who has shed 18 percentage points of support since a late-October version of the same poll.
Cruz's rise and Carson's fall aren't happenstance, the poll found: Among "very conservative" voters, Carson has dropped 23% while Cruz has risen 23% since late October.
It's not the only evidence of Cruz's momentum: A Des Moines Register/Bloomberg Politics Iowa poll shows Cruz surging to a 10-point lead over Trump in the first state to vote in the presidential nominating process.
Those four are the only Republican 2016 contenders polling in double digits. They're trailed by former Florida Gov. Jeb Bush at 7% and Carly Fiorina at 5% -- with no other Republicans higher than 3%.
The poll of 400 Republican primary voters was conducted December 6-9. Its margin of error is plus or minus 4.9 percentage points.