More than two-thirds of Iowa Republican voters surveyed said President Barack Obama is waging a war on Christianity, according to a Public Policy Polling poll released Tuesday.

Thirty percent of GOP voters surveyed said the religion of Islam should be illegal.

The poll came as Republican presidential candidate and retired neurosurgeon Dr. Ben Carson doubled down on his belief that Muslims should not be President and Republican presidential frontrunner Donald Trump suggested the country already had a Muslim President on “Meet The Press.”

The poll was conducted among 488 “usual Republican primary voters” from Sept. 18 to 20 with 80 percent completely the poll by landline. The margin of error was plus or minus 4.4 percent.