There’s been a lot of “communist” talk on the midterms campaign trail. It’s become Trump’s favorite new perceived threat coming from the left. But it’s actually not new at all.

US politicians, especially on the right, have long described communism as a threat to the American way of life. As a result, the United States has undergone historical periods of intense and occasionally violent means to suppress the spread of communism. Beyond the clash between capitalism and communism as economic systems, a line is often drawn between communist ideology and religion in America, specifically Christianity.

In the 1950s, President Dwight D. Eisenhower added the words “Under God” to the Pledge of Allegiance, doubling down on the Christian values of an anti-communist America. The phrase “In God We Trust” was also added to US currency. As evangelical Christians grew into a crucial voting bloc for the Republican party, communist accusations against the left have appeared now and again to mobilize the base.

Hosted by Kahlil Greene, this video is part of our new series Kahlil Explains that unites Vox’s unique brand of explainer journalism with Greene’s expertise in how politics and culture shape society. This episode traces the history of communism in America and its clash with religious groups to unpack why Democratic candidates are being labeled communists and whether the strategy will resonate with voters today.