The George W. Bush candidacy and presidency represented a shift to the right in republican politics, that caused people like Vermont senator Jim Jeffords to leave the republican party. As the GOP has marched further rightward, thoughtful conservatives and republicans have abandoned GOP orthodoxy, sometimes continuing to identify as conservatives (Bruce Bartlett), and sometimes changing sides altogether (David Brock). I think Donald Trump represents the last chance for conservatives to get off the crazy train.
Why did people leave the GOP? I would say the main reasons were disregard for truth (Brock, Bartlett), hateful speech (Charles Johnson, John Cole), and the prominence of “colorful” politicians such as Sarah Palin that showed little intelligence, competence and coherence (the Obama republicans who defected in 08 because of Sarah Palin).
Donald Trump has all three qualities in abundance. If Trump becomes the GOP nominee, it would be very hard for any remaining conservative to continue to pretend that the GOP is about lofty ideals such as limited government and strong national security. I think whoever sticks with Trump will have missed the last chance to return to sanity, and will go down the path of Glenn Beck
