Well, Libertarians are just pot smoking Republicans, so this isn't a huge surprise. Even on foreign policy, the Republican Party has sharply drifted into the direction of isolationism, so this is aligns well.
I was about to say this. Most self-identified libertarians from the mid 2000s up through basically 2016 were just conservative Republicans who didn't want the baggage of having to admit they were associated with George W. Bush. They opposed gay rights, they supported police brutality, a lot of them didn't even really care much about marijuana. They voted for Republicans, they just didn't want an R next to their name.
