The reason I think a primary challenge would be a net good is because I believe that Trump is weak and that his weakness is likely to hurt both the Republican party and the cause of conservatism in the long run. I want the Republican party to have a future after Trump and I think that the best way to achieve that is for a serious conservative to lay the foundation for a post-Trump GOP that preserves conservatism and can compete electorally now, as part of a primary campaign.
Because as things stand, the voting coalition assembled by President Trump is not going to be viable for much longer.
Trump’s 2016 election was built around non-college-educated, white voters over the age of 65. This is not a growth stock. And according to an analysis of the 2018 election by the Pew Research Center, “majorities of voters ages 18 to 29 (67 percent) and 30 to 44 (58 percent) favored the Democratic candidate.”
It used to be a truism that younger voters always trended liberal, but then grew more conservative as they got older. As pollster Kristen Soltis Anderson has noted, that truism is no longer accurate: younger voters aren’t getting more conservative with age and they’re particularly antagonistic toward this incarnation of the Republican party.