We should pick one candidate to all vote for in the Republican primaries.
There's no Democratic primaries this year and we're stuck with Biden. We don't have to be stuck with Trump as his opponent. If someone else wins the Republican primary, Trump will run as a third party candidate and split the fascist vote.
And it doesn't matter which one. Any non-Trump nominee will drag down Trump and vice versa. I'd suggest whoever comes in second in Iowa, just because they're the most likely to have any momentum at all.