Elon Musk attacked Kamala Harris as an “extinctionist” in a particularly unhinged X post on Saturday. The billionaire was commenting on another post penned by Donald Trump’s running mate, Sen. J.D. Vance (R-OH), in which he attacked Kamala Harris for saying that the threat of climate change has played a part in many people’s decisions to have kids—among a number of other major life decisions. “It’s almost like these people don’t want young people starting families or something. Really weird stuff,” Vance wrote. Musk took Vance’s criticism to the absolute extreme, arguing that Harris’ acknowledgement of so-called “climate anxiety” among young people meant she was advocating for the “de facto holocaust for all of humanity.”