As Elon Musk and Donald Trump feuded, conspiracy theorists assured their followers it was all a show. "5D chess at its finest, baby—checkmate!” proclaimed one.

President Donald Trump has doubled down on what appears to be his new favorite conspiracy theory in a late-night, all-caps Truth Social meltdown. Last week, Trump sounded off about “the Biggest Scandal in American History”—other than the “rigged” 2020 election—claiming someone had “usurped” a mentally declining Joe Biden and used an “autopen” to push through a radical-left agenda while Biden was president.