Will Trumpism die as quickly as it rose assuming Trump loses in 2020?

[Brother Jonathan]

If we understand "Trumpism" to mean economic populism/social conservatism (esp. on issues of culture) coupled with nationalism, then no. There is a natural resonance for much of these positions in the GOP base, and Trump's defeat won't break some magic spell and suddenly reset the discourse. At the risk of regurgitating the old line, "Trumpism" is more of a symptom than a problem and so it will have a resonance in the party moving forward. Most likely, though, it will decline in influence. The GOP currently is towing the "Trumpism" line so closely largely because Trump is President, and so he sets the agenda, but in opposition the GOP would probably fracture a fair deal. There is going to be a lot of tension between the economic populists and conservatives in the party, which I think may prove to be the defining fault line in the party moving forward.

Electorally, it will be damaging unless the messaging can be made to resonate either with minority communities or suburbanites (or both). If suburban voters continue to drift away from the GOP and minority communities remain unreached, then the party will be forced to abandon "Trumpism" or face electoral oblivion. If in 2024, however, Josh Hawley or Tom Cotton or Someone  manages to break 25% of the black vote and carries Orange County handily, then "Trumpism" will be here for a while.

In any event, the national dialogue and the Republican party especially have been changed by "Trumpism" and its legacy will linger for quite some time even if specific aspects of it change over the coming years.