Probably a bit less of an impact than whatever comes out of Iowa.
And the Iowa Oracle has weighed in: Selzer & Co. has Trump 28, Cruz 23, Rubio 15, Carson 10, Paul 5, and everyone else 3 or less.
This poll was taken January 26-29, so that only included one day of post-debate polling. Sample of 602 likely GOP caucus voters, MOE +/- 4%.
Upsides and downsides: 71% of Trump’s supporters say their minds are made up, v. 61% for Cruz and 47% for Rubio. But Trump was the second choice of only 7%, v. 17% for Cruz and 20% for Rubio.
Trump’s and Rubio’s support have both been increasing over the past several weeks: in mid-December, Selzer had Trump’s support at 21% and Rubio’s at 10%. But the number of people considering Rubio for their second choice has grown, while the same number for Trump has shrunk: in December, he’d been the first choice of 21% and the second choice of 14%; now it’s 28 and 7, which suggests that he’s firming up his support among voters who’d been considering him, but not widening his potential base.
So Trump’s support in Iowa really is what it is at this point; the only question about it is the perpetual ‘will his supporters turn out’ question. While Rubio’s support could still go a ways in either direction: he’s the second choice of a lot of people, but his support is soft even among those who have him as their first choice. And Cruz is somewhere in between.
And of course Cruz is the only one of the top 3 whose support has been decreasing, down from 31% in December.
Carson seems to have arrested his slide. He won’t win, but he’ll probably still get 9-10% of the vote.
Other than Rubio, none of the ‘Establishment lane’ candidates appears to have any prospects of getting a bounce out of Iowa to help them in NH. Rand might, though.
And of course, Monday night will be the end of the line for Huckabee and Santorum, whose hopes are on an Iowa miracle that won’t happen.