One moment of vulnerability for Mr. Trump stood out as a missed opportunity for Mr. DeSantis.
When the former president said in September on NBC’s “Meet the Press” that Mr. DeSantis signing a six-week abortion ban was a “terrible mistake,” internal metrics showed his support among the most conservative voters dipping. To the Trump team’s surprise, the DeSantis operation did not quickly seize on the remark and amplify it in paid media. Soon Mr. Trump had recovered, with a blitz of direct mail targeting social-conservative voters in Iowa.
By the fall, the DeSantis operation was mired in a mess of dysfunction. The campaign had run short of money over the summer, so the main super PAC supporting him, Never Back Down, shouldered a growing burden. But as the super PAC tore itself apart with infighting, resignations and firings, DeSantis allies formed a new group, Fight Right, to run anti-Haley commercials.
The focus of Fight Right’s anti-Haley ads seemed to mirror exactly what the DeSantis campaign wanted. But internal data from Never Back Down, described by a person familiar with it, showed that the ads that Fight Right was airing were using topics, including Ms. Haley’s stance on transgender issues and the suggestion that she was inspired by Hillary Clinton, that might have actually been helping her among some of the persuadable voters left in the Republican primary.
Ken Cuccinelli, a Never Back Down board member, objected at one point to Fight Right’s anti-Haley ads, saying in an internal message that the ads from the DeSantis group should be treated like an in-kind contribution to Ms. Haley, according to the person who described the correspondence. Mr. Cuccinelli resigned from the group’s board in December, though his departure has not previously been reported, and he stayed on as an adviser.
As Iowa neared, it was Ms. Haley’s surge that was the cause for concern for the Trump team. His advisers never worried that she might defeat the former president in the state. But they knew that if Ms. Haley finished a strong second ahead of Mr. DeSantis, there was a risk that she could shoot out of Iowa with enough momentum to eclipse Mr. Trump in New Hampshire.