What If: The US Government Cracked Down On Scientology
Still self-banned from the alternate-history forum and likely to stay that way, but the users whose handles are GeographyDude and WhiteDragon25 posted an interesting alternate timeline in which the U.S. government cracks down on Scientology.
Why would it do that, you ask? Doesn't the U.S. Constitution protect religious freedom? Yes it does, but the Church of Scientology itself is involved in a lot of nefarious practices. The trigger in this alternate timeline is that when the FBI raids Scientologist offices in the late 1970s as part of the investigation into Operation Snow White, things go a bit pear-shaped and the Scientologist leaders are able to get word out to their agents in the IRS and other federal agencies.
(Yes, there was an extensive Scientology espionage/infiltration operation against the U.S. government. I wish I was making this up.)
Said agents panic and make mistakes, screwing up IRS records and Americans' getting their tax returns processed in a timely fashion. This spins up quite a lot of outrage against the "Church" once word gets out as to who is responsible. The number of FBI raids mushroom, more abusive Scientologist practices are exposed, and Scientology founder L. Ron Hubbard himself ends up sentenced to a lengthy prison term. Given the widespread fears of New Age cults at the time (the fact that deprogramming was acceptable speaks volumes), I could easily imagine Scientology getting no mercy from the justice system or the wider public.
This in turn leads to a wider crackdown on cults and even more mainstream religions, although I think some of the commentary on evangelical mega-churches does seem like it's shading into wish-fulfillment territory. That said, given some of the televangelist scandals of the later 1980s, it's not like there weren't sins and crimes committed on that front either.