“The one thing that’s remained absolutely consistent is his penchant for conspiracy theorizing,” Uscinski said.

Polling during the primary showed that Trump was especially popular with Republicans who endorsed conspiracy theories.

His supporters were more likely than supporters of Sen. Ted Cruz (Tex.) and Ohio Gov. John Kasich to agree with the statement, “President Obama is hiding important information about his background and early life,” according to the data from Fairleigh Dickinson University in New Jersey.