Republican presidential front-runner Donald Trump's campaign isn't slowing down, at least when it comes to national polling.
In a new NBC News/Wall Street Journal poll published Thursday, Trump reached his highest number yet in that survey.
The poll found that Trump was the top choice of 33% of Republican primary voters.
That gave him a 13-point lead over the No. 2. Republican, Sen. Ted Cruz (R-Texas), who had 20% support.
See some of Donald Trump's biggest supporters:
NBC News reported that Trump's margin over Cruz sharply increased since last month, when the same poll found five points separating the two candidates.
In the survey released Thursday, Sen. Marco Rubio (R-Florida) was the first choice of 13% of primary voters, followed by retired neurosurgeon Ben Carson's 12%. Former Florida Gov. Jeb Bush (R) and New Jersey Gov. Chris Christie (R) both had 5%, while no other candidate had more than 3%.
Although Trump is dominant in national polls, the first state to weigh in on the primary, Iowa, is not as friendly turf for the real-estate mogul. Cruz has placed first in a number of recent surveys of likely Iowa caucus-goers, who cast their votes on February 1.
PHOTOS: Click through to see more from Donald Trump's 2016 campaign
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