The RNC declared Trump to be the leader of their party after he told a crowd of armed terrorists that they should go to the Capitol and "save" the country from the politicians who were busy certifying the results of an election. They did so after that same crowd stormed the Capitol building, replaced the American flag with a Trump flag, and proudly declared to the cameras that they were there for a "revolution."

Kind of hard to know where the line is drawn between "declaring as your leader the man who advocates for a violent overthrow" and "advocating for a violent overthow."