Nah, We have some corruption but nothing as bad as the early part of this century. The robber barons of industry like Hearst, Getty, and Rockefeller had way more power over government policy back then. Fucking Hearst and his timber industries alone criminalized pot because they viewed it as a threat. And this was during a time when the Prohibition movement managed to have alcohol outlawed. Cut to today and drinking beer is an American pastime while pot is still illegal. That's real power and a good smear job imo.
First off, a semantics correction: America is a Federal Republic, not a Democracy. If it were truly a democracy, like Ancient Greece, we would all vote on everything, and that would take up too much of our valuable time. Hell, we can't even get 40% of us to vote once every four years.
I think the system we have is the best choice we have for the society we have chosen. Sure, it has strayed far from the founding fathers' intents (Congress being the most powerful branch, followed by the President, then the Supreme Court), and the checks and balances don't work as well as they should, but it beats the hell out of all the other forms of government in the world at this point.