The very thing needed for a democracy to genuinely work at a national level is for people to be of one mind. That is obviously not the case in the United States and hasn't been since, well, ever. Even the American Revolution was driven by the minority of the population, as was, quite frankly, the Civil War. Today, the country is pretty sharply polarized, and no group really trusts each other and nor should they. We have liberals and other statists (including neoconservatives), evangelicals, libertarians, anarchists, all of them who have an idealized life that is completely different. Add to the mix of wide political outlooks that include continual race and gender based politics and political argument, and you've basically a country that can't help but be in a continual state of gridlock.
My ideal case is to deconstruct anything about the government. I resent that the courts have so much power over my family that they have soured my ability to trust any kind of governmental power whatsoever and my only answer is to vote to shut it down. This libertarian idea is impossible to reach, so the best bet is to let the powers that be bash each other, so, I always vote for divided government. Shut it all down, I say, at the Federal Level, then break up the states next!