Bill Weld got a fairly decent 9.2% of the vote in the NH Republican primary. Argue over what the self-proclaimed "Libertarian for life" Republican is worth, but this was where the not-Trump vote went.
There's a decent number of folks who want a President Not Trump who chose to vote in the Democratic primary. If it were the same set of people who voted in the R primaries in 2018 or 2016 I think the number would be higher than 9.2% (though probably still a majority).
Liberdon is a Mastodon instance for libertarians, ancaps, anarchists, voluntaryists, agorists, etc to sound off without fear of reprisal from jack or zuck. It was created in the wake of the Great Twitter Cullings of 2018, when a number of prominent libertarian accounts were suspended or banned.