Sorry for the semi-necro, but this is actually the thread that inspired me to register here.
Welcome!
I can easily see a scenario following on from Columbine in which the Satanic Panic of the 1990s takes a genuinely apocalyptic turn after the Millennium. All it would require is a few copycat shootings just after Columbine; so much the better if anyone involved were actually Marilyn Manson fans (Harris and Klebold weren't). Karl Rove and the Bush 2000 campaign surely wouldn't be above overtly politicizing such a scare, and they'd do it in explicitly theological terms.
What ends up happening is that Bush essentially runs his 2004 election campaign four years previously (despite the Lewinsky Scandal, Bush didn't hit moral or religious themes nearly as hard as he would; the re-election campaign was essentially won on opposition to gay marriage in Ohio). Whether this would be a winning strategy is a matter for debate - but Al Gore would probably tack right on moral issues to combat it, and he'd have the credibility to do so, given his relationship to the aforementioned PMRC.
A lot of subtle butterflies flying around here.
That's a very interesting PoD. And I can really see it happening in the years before 9/11. What I'm less sure of is how 9/11 would impact it. I'm not sure there's room in the zeitgeist for two Evil Enemies.
Beyond that, something which I don't think we've addressed yet is, if the Satanic Panic does get worse, either the first or the second, what form does it take? If there's all this panic and fear swirling around about Satanists In Our Midst, what do people and politicians do about it, besides send more innocent daycare workers to prison?
Purely hypothetically, could it get bad enough to reach the level of some kind of internment? Actually outlawing heavy metal or whatever is a transparent first amendment violation, and would get nowhere. But if you convince enough psychologists and judges that listening to Marilyn Manson or Ozzy Osbourne is prima facie evidence of mental disturbance, then you don't need to actually outlaw it. You can give it the legal cover of "we're not arresting these people, we're committing them to mental institutions." I have a hard time believing it could get that bad, but I didn't really start paying attention to politics until after 9/11, so I don't know.