Emerging onstage in San Antonio, Letterman offered vague hints about his previous whereabouts, then proceeded to deliver 10 threats to Trump’s presidential legitimacy. Disguised by a silvery beard and backed by longtime supporters Steve Martin and Martin Short (two of the infamous Three Amigos), Letterman fired off jabs like “No. 8: Donald Trump looks like the guy in the life boat with the women and children,” offering no less than four jokes about “that thing on [Trump’s] head.”