They hate Donald Trump and his 80 million MAGA supporters for the exact same reason the British Crown and the Loyalists hated George Washington and his fellow Founders throughout the first American Revolution:
He aims to take the power away from the ruling class and return it to the citizens.
This isn’t about Republican vs Democrat anymore. But the Republican Party constituency will be far easier for MAGA to reason with - since the average Republican voter’s IQ is a good thirty points higher than that of the average a Democrat voter, and their rural demography is far less corrupted than urban socialist Democrats.