Want to know the best indicator of how a South Dakotan might vote? Find out their religion, according to Sioux Falls pollster Paul Nielson.

“If you’re evangelical Christian, you’ll almost certainly vote Republican,” Nielson said. “A mainline Protestant, probably a little more Republican than Democrat. Roman Catholic has tended to be more Democratic, but actually in this election, they went more Republican, according to our polling, toward the end, which was a really bad sign for Democrat.”

And what about the un-churched and non-Christians?

“Unaffiliated tends to be more Democratic and someone involved in some sort of other religion also tends to be little be more Democratic,” Nielson said.

For Democrats, according to Nielson, about the only clear constituencies they won in this month’s election were reservation-based Native Americans and non-religiously affiliated voters.

Nielson, a partner in Nielson Brothers Polling, surveyed South Dakota voters and statewide candidates and issues throughout the 2014 election. NBP also did tracking polls on the major South Dakota races and issues in the last two weeks of the general election.

Nielson made his comments Friday on KSOO-AM’s Viewpoint University call-in program.