Asking voters at Cruz and Rubio events who they support often elicits a comment about Trump. My own experience is that earlier in January, voters at Cruz townhalls were likely to tell me they were on the fence between Cruz and Trump. Now, they’re more likely to say they’ve chosen Cruz — an anecdotal illustration of the Register’s finding that more Republicans are set in their choices, even though a significant number say they could still change their minds.

Rubio voters seem more likely never to have seriously considered Trump. But even if they did, they’re over it now.

“Trump has been in the news all the time,” a man named Gary Swanson, from Sioux City, told me at Rubio’s Sioux City event. “We were not for him, but then we were kind of on the fence with him. And he makes the statement that he’s so popular that he could shoot a person on Fifth Avenue without losing a vote. Well, he just lost two right here when he said that.” Swanson and the friend who came with him are now supporting Rubio.

On another Trump question, it’s hard to tell how boycotting the debate will affect him; Cruz and Rubio rallies are not exactly the best place to find Trump supporters. But one thing that is clear is that a huge percentage of Iowa Republicans who are trying to make up their minds watched that debate. It just stands to reason; people who were only mildly interested a few months ago are more interested in the final hours before voting, and they turned their attention to the only GOP debate held in Iowa before the caucuses. And Trump, who has been a commanding figure even in debates he didn’t win, wasn’t there. It’s hard not to see that as a mistake on Trump’s part, but we’ll know more later.