This is happening throughout the Democrat Party. But "Trump is destroying the Republican Party"
I do see honorable Democrats--real Americans--figuring out the DNC no longer represents them, their values, their interests. It's tough, stressful, even gut wrenching making the decision to leave a church, political party, other organizations that you have loved and supported for decades, but sometimes honorable people come to that decision when those no longer represent them and what they believe to be good and right. I know because I have been there.
As for the Republicans, I think Trump has been one of several strong catalysts to inspire the GOP to become the party of real Americans, those who love America and want it to be strong, free, secure and prosperous, who support tried and true traditional values and traditions, and who still think those values require personal responsibility and accountability.
The old guard neocon globalist GOP hates him because he succeeded where they did not, he achieved success where they said it couldn't be done or didn't even seriously try, and he showed them up for the feckless, ineffective, timid people they had become.