The retired neurosurgeon from Baltimore has 28% of Republican primary voters’ support in the Hawkeye State, according to the latest Bloomberg/Des Moines Register poll. Carson first gained political fame after denouncing President Obama to his face at the 2013 National Prayer breakfast, and he hasn’t stepped off the national stage since.

Carson’s lead in Iowa is likely on account of one simple reason—unlike Donald Trump, he is running the kind of divisive campaign that particularly appeals to Christian conservatives, who account for a significant portion of Iowa Republican Caucus voters.

Evangelical Christians make up about 60% of Iowa’s Republican Caucus attendees, according to the New York Times. They have an outsize influence on this contest, which just happens to be the first in the nation. The victors of the last two Iowa Republican caucuses were Mike Huckabee and Rick Santorum. (Santorum just barely edged out the eventual Republican presidential nominee Mitt Romney.) Both of those candidates based their campaigns on their religious conservatism, making issues like gay marriage and abortion their primary talking points.

Carson is a devout Christian and he’s not afraid to talk about it. He has taken it even further, though, saying that he didn’t think a Muslim should be president and doubling down on that notion when asked about it again. When addressing the subject of gun control, he has asserted that arming Jewish people could have helped to prevent the Holocaust. Gun control isn’t, strictly speaking, a Christian values issue, but it’s an issue that does hold sway with cultural conservatives.

Trump, on the other hand, has played the racial division game more than the religious one, with his blunt talk about immigration and his controversial campaign announcement in which he called illegal immigrants rapists. Iowa is around 87% white, according to census figures, and only around 6% Hispanic or Latino. Anti-immigrant rhetoric doesn’t have the same impact there as it might have in states where the portion of non-white people and immigrants is higher.

All political campaigns are, at the end, at least a bit about division. The rhetoric of many on the left is about setting the working class against the rich, as anyone who has listened to a Bernie Sanders speech can tell you. The differing campaign tones taken by Carson and Trump sets them apart. And, at least in Iowa, Carson’s seems to be resonating more than Trump’s.