Lynn Vavreck notes that the Republican Party has gone off the equilibrium path:

Given that they want to win elections more than anything else, parties rarely make catastrophic mistakes in nominating candidates for president. Because of that, it is easy to believe that who the candidates are and what they say has little effect on presidential election outcomes, especially in this period of heightened partisanship and party sorting.

But they do. Just because we rarely see it doesn’t mean it isn’t real.

This is a nuanced point and also crucial to understand that this mistake does not mean that parties have been disrupted or otherwise broken. The G.O.P. will figure this out before 2020.