The Republicans really didn’t want Trump in 2016. Jeb Bush was their boy.
The Democrats wanted Hillary to be Obama’s heir….
Only the people wanted Trump. So when it came re-election time, there were powerful forces, on both sides, against him. This is why Trump had massive crowds of supporters. but lukewarm support in Congress and also the GOP. The Democrats connived to get rid of him by any means necessary, the establishment GOP didn’t lift a finger to help Trump either