Don't get me wrong, I hope we never have the need for violent/armed resistance. I do think the powers that be are kept in check to a certain degree because such resistance is a possibility and because they realize it would be impossible to squelch
Quite impossible to prove, quite impossible to prove the powers that be are kept in check either (I mean if "in check" doesn't stop things like the NDAA, torture, presidential murder, crackdowns on dissent, drones over U.S. cities, cops killing innocent people ...) then it's not exactly particularly effective. But it could be worse? Well things could *always* be worse... So how would one know things are kept in check or not?

There's an alternate argument that the powers that be become more militarized themselves in a heavily armed society, they put on the full riot gear and Mayberry orders a tank, a type of arms race (although to some extent this is more widespread than just in the U.S.)

Never mind that it seems impossible to get a critical mass to keep anything in check just via normal civics stuff (voting in a meaningful way - not lesser evilism!!!, protest, etc.). So people too indifferent to even bother but they want armed revolution, well if that's the case, it's really messed up. I would like to have seen everyone who wants to keep things in check via guns to form mass protests to the NDAA. Yea, nada (excuse my anagram).