Amon has the right balance of intellect and power to fuel his position. You guys remember how Hitler was before WW2? Time magazine's "Man of the Year"? What's going to happen, is that Amon might do something stupid and "bite off more than he can chew" like Napolean or Hitler did. But so far, Amon has been playing his cards right, even sparing the Avatar to make sure he doesn't bring on too much more than he can handle (the entire world being involved in Republic City).
With that said, I completely agree with MrBlack. You can't fight ideology with brute force. That's the reason why things like Christianity persisted throughout the first few centuries AD. In order to defeat Amon, you need to start teaching why Bending is great, and equality is not really an issue. That's what Korra is supposed to do, but, as was noted previously, Korra gets the physical side -- the brute force -- but completely ignores the spiritual side.
That's what I like about this series though. In TLA Aang had the spiritual side down. But he needed the physical. In LOK, it looks like Korra is pretty great physically, but lacks any real spiritual prowess.
"But when this higher road comes down we'll be born together,
and when this higher road comes down we'll be born forever"