John Sauer, a lawyer arguing Donald Trump’s presidential immunity case, generated significant controversy when he asserted that a president could not be prosecuted if he were to order the assassination of a political rival — unless he were first impeached and convicted. The former solicitor general of Missouri, Sauer is no stranger to the Supreme Court or to controversy. He has filed many briefs before the high court in his role with the Missouri attorney general’s office — including one pressing justices to toss out the 2020 election results in key swing states. Sauer has also been involved in an anti-abortion case that created a national firestorm, and has used the power of public office to attack reproductive rights and Planned Parenthood.