Yet another poll shows Donald Trump leading among Republican voters, and his virulently anti-Muslim policies and rhetoric only seem to be helping him gain support.

Public Policy Polling today released the results of its latest Iowa survey, and found that a substantial percentage of Republicans in the first-in-the-nation caucus state, including a majority of Trump backers, are in favor of closing mosques and establishing a database monitoring all Muslims.

A majority of Republicans in the state also back Trump’s proposed ban on Muslims from immigrating to the U.S.

Unsurprisingly, a plurality of Trump’s Iowa supporters also backed the internment of Japanese-Americans during World War II.