For the third time Republicans looking to become President square off. This time... with a new front-runner.
FOX News Radio's Jared Halpern has more from Boulder, Colorado:
As has been the case twice already, the large Republican field is split into two groups: the higher polling ten candidates in prime time, the lower polling four in an earlier under-card.
Both stages will look nearly the same as last month, minus Wisconsin Governor Scott Walker, who has ended his bid.
What is different... the top of the GOP field. Retired neurosurgeon Ben Carson now leading a few polls in Iowa and a new national CBS/New York Times poll.
Trump is still running second, well ahead of the rest of the pack, but has spent this week not just critical of those polls, but also Carson, who he calls low-energy.
In Boulder, Colorado, Jared Halpern, FOX News Radio.