It's been happening longer than that. I used to post in a local Pittsburgh group on USENET before groups like FR were big (pgh.opinion) which the local LP members used to write to. They were big cheerleaders of the ALCU and unlimited immigration, illegal or otherwise.
I met a number of principled libertarians back in the 90s.
Real hard-core Jefforsonian liberals. ( By Jeffersonian liberals I mean people who were 100% in favor of individual liberty.) Now I see appeasers, Marxists, socialialists, etc., calling themselves libertarians. That’s a real shame. I’m getting tired of the damn friggin’ marxists taking over all our good organizations.
A day of reckoning is coming soon.