Why do conservatives still believe in Reaganomics even though in the long run it was a disaster?

I mean yeah at first it worked, but within a few years the economy was in shambles and it took the Clinton administration to fix it. Then Bush Jr came along with the same failed Reagan/Bush Sr economic policies (tax cuts for the rich, let it trickle down etc) and that didn't work either. So why do they still think it's gonna work?!