Just one correction: until about four years ago, Trump gave about equally to each side. He has only given to Republicans recently. My sense is that the drift of the Democratic Party into the radical left-wing agenda became too much for him. Curiously, his probable opponent in the general will be a candidate that, in 2008, represented the centrist position within the Democratic Party; although, in 1992, she was to the left of center within that party.
It is easy to predict what agendas Hillary Clinton or Ted Cruz would pursue as POTUS based on their past performance. If I vote for Trump in the general election, it will be a roll of the dice for me. Hopefully, we would get the GOP primary Trump that does not shy away from conflict and not the Trump that spent most of his adult life buying influence through campaign contributions. We do not need a go along to get along Republican in the White House.