The latest article by The Atlantic’s Adam Serwer explains why Republicans won’t turn on Trump in light of impeachment, but rather, will dig in even deeper:
Attempting to use one’s official powers for private gain is the most basic definition of corruption. Yet because the base of the Republican Party believes itself to be the only legitimate expression of popular will, whether or not its members constitute an actual majority of the electorate, it does not matter what Trump’s motives are. Much of the Republican base believes, as Trump does, that loyalty to the country and loyalty to himself are one and the same. Therefore, nothing Trump could do is corrupt, and even using his official powers for personal gain is an act of selfless patriotism. In this warped view, attempting to extort foreign countries into attacking his political rivals is not a betrayal of his responsibilities as president; it is the fullest expression of them.
Unless Republican support for Trump craters, Republican legislators will not turn against him. And Republican support for Trump cannot crater as long as many Republicans view their political rivals as illegitimate political actors rather than fellow citizens.
Serwer also excoriates Democrats for dragging their heals on impeachment: “[W]hen the president attempted to use his authority to extort a foreign leader into implicating one of his political rivals, a former vice president and longtime Democratic senator, in criminal activity, the leadership of the Democratic Party seemed to suddenly recognize what it was facing.”