“The bet­ter Ben Car­son does, the worse Ted Cruz will do,” said Jam­ie John­son, an Iowa pas­tor who worked on Rick Perry’s 2016 pres­id­en­tial cam­paign. “I still have talked to people this very week—they love Ben Car­son, and they’re go­ing to caucus for him. And that does not bode well for Ted Cruz.”

Re­cent polling sug­gests Car­son, who re­mains ex­tremely pop­u­lar among GOP voters even if he’s no longer their top pick, is eat­ing more in­to Cruz’s po­ten­tial base of sup­port than Trump’s. Cross-tabs provided to Na­tion­al Journ­al from a mid-Janu­ary Lor­as Col­lege sur­vey of likely Iowa Re­pub­lic­an caucus-go­ers showed 37 per­cent of Car­son back­ers say­ing Cruz was their second choice, com­pared to 27 per­cent for Marco Ru­bio and 10 per­cent for Trump. And nearly half of Car­son’s sup­port­ers said they were ab­so­lutely com­mit­ted to caucus­ing for him.

Pre­vi­ous cycles have proven that the fi­nal week in Iowa is pivotal, so Car­son could bleed more sup­port by Monday. Sev­er­al of his seni­or staffers have left the cam­paign in re­cent weeks, and the polit­ic­al new­comer has yet to find the abil­ity to clearly ar­tic­u­late his views on na­tion­al se­cur­ity at a time when the is­sue is at the fore­front of voters’ minds.

Still, he’s con­tinu­ing to hit the pave­ment in Iowa. Through Tues­day, Car­son had spent 12 days in the state this month, com­pared to ten for Cruz and Ru­bio and eight for Trump.