At that point, many in the GOP base will still remember him fondly, and Republicans will need to integrate the remnants of Trumpism into their next ideology. But as an ideology, Trumpism is an inscrutable collection of instincts, insults, rants and tweets. Aspiring GOP leaders will try to bend the material into something comprehensible, but there will be no way to judge who is “right” about what Trump would have done on any issue, aside from immigration. Like a perverse Bible study, Republicans will pore over Trump’s words looking for a divine political message, and they’ll all come away with flawed, irreconcilable interpretations.
Eventually, Republicans will solve this problem. Political parties, unlike religious groups, nominate their leaders in primaries. Might will make right, and the candidate who offers up the most popular version of Trumpism-plus-their-ideas will win.
The best realistic endgame for this fight: Republicans find someone who takes stylistic cues from Trumpism, fighting the media and throwing red meat to the base while taking governing and policy seriously and pursuing them with real competence. In the Bible study metaphor, he or she would be a theological conservative who takes the text seriously but doesn’t think humans hung out with dinosaurs.
But much darker scenarios are on the table, too.