Elon Musk and a German far-right leader appeared to come to a truly bizarre agreement during a livestreamed X chat Thursday: Adolf Hitler was a communist. Musk had been plugging the chat with the AfD (Alternative for Germany) co-leader Alice Weidel for days,

The publicity was a potential boon for AfD, which has been frozen out of mainstream politics, in part, because its leaders have downplayed Nazi atrocities.

Political leaders have shunned the Alternative for Germany. But on his social media platform X, Mr. Musk is pitching the party as mainstream.