It is really pretty simple. The Republican party is highly dysfunctional. Anyone, and everyone, with two brain cells knows that the more Republicans that enter the race for president the more likely it is that Trump will win the nomination. And already, at this early point, there are almost a dozen candidates for the Republican nomination. I mean they are all fools.
Trump has a base. Yes, they are all a bunch of old white dudes, most living in the damn sticks and flying the Confederate battleflag in their front yard. They drive pick-up trucks and pack heat because of their insecurities. And bless their hearts, they are dumber than a box of damn rocks. The smartest of them all graduated from a podunk high school, many of them never even accomplished that.
So Trump wins the primary. No way in hell he can win the general election. And worse, he will drag down the rest of the ticket. Republicans lose the House, Democrats expand their majority in the Senate. Hell, Trump is the gift to Democrats that keep on giving and all because a huge swath of the Republican party is too stupid to realize how toxic the man is.