The very basics on the John Birch Society is:
Anti-Communism: Which I'm definitely onboard with. It's a One-Party-Only government and ALL One-Party-Only governments are authoritarian, oppressive, persecutory, tyrannical and murderous to their own people.
Conservative: Against frivolous spending, especially towards giving its citizens hard-earned dollars to huge numbers of people flowing over our border.
Pro-Populist: That's a silly complaint to be against. It only means a politician who strives to appeal to a large number of the common people. For that matter any politician that wins by the popular vote, can be defined as a populist candidate.
The claim that supporters are "far-right wing: Frankly, any candidate that the far-left, Neo-Marxist, pro-Communist left disagrees with are immediately tossed into the category of being "far-right wing," even though that's not factual. I was in the military when John F. Kennedy was president and based upon those things he did, today's leftists would label him far-right wing, which he wasn't. But, he was one of my favorite presidents.
Anti-Collectivism: Pro-individual liberties. Succeeding on your own merits.
Things I'm NOT onboard with regarding the John Birch Society:
Being Pro-Libertarian.
Conspiracy Theories.
Civil Rights Movement.
Equal Rights Amendment.
Federal Reserve System.