America hasn't been a democracy for 200 years. Some would argue that we've been there for about 100 years, but in fact, the republican roots built into our Constitution have protected us from becoming a full-on democracy.
Sure, we're far closer than we'd like to be, but not quite all the way there. And if recent (and developing) history is any indicator, we're near to forging back toward that republican ideal with a vengeance.
A republic goes to democracy, and end in tyranny. The cycle is around 200 years.
Republics decay with the expansion of the franchise. Democracy falls when people start voting themselves money, and stop working. In the end, the mob will scream for a leader to save them.
We are nearing that point.