Again, who does the GOP have to replace Trump??? IF Trump does NOT do something to resolve the current border crisis and the continual influx of illegals, we lose this Republic. Pure and simple. The other problem @Jazzhead is the issue needs to be resolved now. We're out of time and Trump is who we have. The crisis at the border isn't fictional. The fact that they are overwhelmed at the border and our border agents are letting them in without vetting is a fact. If we remain on our current course, how long do you think it will be before we are another Europe?? IMHO, at best, a year.
There are plenty of good Republicans who could replace Trump. However, the dynamic is that Trump would need to voluntarily step aside; he won't be effectively challenged in the primaries if he insists on running for re-election. If he does and wins, I fear, given his age, that he will never return to private life. But more to the point, I fear he cannot win.
I am in the camp that believes he viewed his own election as a shock and a mixed blessing. One term is enough for a citizen-politician who is sure of his legacy - and he has genuine accomplishments to tout. Let him retire to his family and his businesses. If he does, I will hail him as a great American.
Now I disagree with most here about the border issue. I don't view it as an existential crisis. But be that as it may, the question is whether the causes of immigration reform and border security will be helped or hurt by a 2020 Trump candidacy. I simply don't think he can win, and fear that his re-nomination will pave the way for a radicalized Dem party that will put the kibosh on conservatives and their priorities. THAT is the existential crisis.
We need to think strategically, and make the rejection of socialism and tribalism - the Dems' two great obsessions - the front and center issues of this campaign. That cannot be done with Trump as the nominee. Simply and charitably put, he is a distraction.