Because that how dictators do.

“President Trump has always stood for law and order, and protecting the Constitution.”; -Trump campaign spokesman Steven Cheung responding to questions concerning rumblings that his boss is planning to invoke the Insurrection Act, establish martial law unprovoked on day one if he regains the Presidency, conveniently forgetting his boss has already floated the notion that the POTUS is under no obligation to protect, obey the Constitution, that calling a violent mob to assemble and attack the Capitol Building, attempt to lynch public officials falls under the purview of Executive Duty.