On June 8, 1967, the Israeli military machine-gunned, bombed and torpedoed the U.S.S. Liberty, an American vessel floating off the Sinai Peninsula, killing 34 service members.

Those facts are not in dispute. But almost everything else about the attack is driving a wedge through the MAGA movement.

On one side are prominent voices like the podcaster Ben Shapiro, Senator Ted Cruz of Texas and Rich Lowry, editor in chief of The National Review. They insist the attack on the Liberty was a tragic case of mistaken identity amid the chaos of the Six-Day War, a conclusion shared by a U.S. Navy Court of Inquiry and the Israeli government.

Those on the other side include the podcasters Tucker Carlson and Candace Owens and Representative Paul Gosar of Arizona. They insist Israel knew the Liberty was an American ship and say the attack is proof that the Israeli government cannot be trusted and is no ally to the United States.

While many Americans have never heard of the Liberty, it has become a topic of obsession on the right, which is increasingly divided over America’s relationship with Israel. Conservatives are split between those who are adamant supporters of the country and those critical of the Jewish state who sometimes employ openly antisemitic views to make their case.

The debate over the six-decade-old maritime disaster, playing out at conservative events, in social media and on viral podcasts, has become a litmus test within President Trump’s movement. Talking about the Liberty has become a thinly coded way to figure out which side someone is on.