The people empowering FPI's coalition (ie. folks like SBY) are "moderates". But just because they're being used as tools to achieve political power, that doesn't mean that they're not gaining more followers and influence. It's all a matter of prestige and appearances. If FPI can be the face of a protest that drew hundreds of thousands of people, then their political and social standing among conservative Indonesians has drastically improved. And Jokowi's decision to appear at the 212 protest further legitimized them in the eyes of the masses.

I mean just recently, they were nothing more than an unpopular fringe group that were glorified extortionists...But now they have major backing by powerful political figures, gathered half a million people to a protest, pressured law enforcement to indict the sitting governor of Jakarta on bogus charges, and managed to share a fucking stage with the President.

Sure, the middle and upper class aren't buying it. But that doesn't count for much when the largest demographic in this country are poor conservative Muslims. That's the demographic the FPI are going for, and their primary competition are 'moderate' groups like NU. Right now they're still behind, but they are gaining more influence.