It wasn’t so much that the new app that the Iowa Democratic Party had planned to use to report its caucus results didn’t work. It was that people were struggling to even log in or download it in the first place. After all, there had never been any app-specific training for his many precinct chairs.

So last Thursday Mr. Bagniewski, the chairman of the Democratic Party in Polk County, Iowa’s most populous, decided to scrap the app entirely, instructing his precinct chairs to simply call in the caucus results as they had always done.

The only problem was, when the time came during Monday’s caucuses, those precinct chairs could not connect with party leaders via phone. Mr. Bagniewski instructed his executive director to take pictures of the results with her smartphone and drive over to the Iowa Democratic Party headquarters to deliver them in person. She was turned away without explanation, he said.

“I don’t even know if they know what they don’t know,” Mr. Bagniewski said of the state party shortly before 2 a.m. on Tuesday.