Trump hates the whole Bush family even after endorsing GHW.
I don't know if it was “read my lips” or what but something happened during the first Bush presidency to cause him to hate the whole bunch of them.
I would like to believe it was because Bush took all of the positives of Reagan and threw them in a pile on the floor but I don't know the real reason.
I’d guess if a person follows the money they’ll get to the source.