The current US government is mostly atrocious, but I'm convinced that the American people have the government they, or we, collectively deserve. Congress hasn't become horribly dysfunctional and stupid because they've somehow become disconnected from the people. Rather, the electorate has become horribly dysfunctional and stupid, and Congress simply follows along.
I think the main problem is that our system is set up so that fringe elements have much more power. Voting happens in the middle of the week and is not an official holiday. Who turns out to vote, then? The people who care most passionately will inevitably show up in much greater numbers than people who are less enthusiastic. Passion is great, all else being equal, but I believe that passion correlates strongly with craziness in the political arena. Primary elections are even worse in this respect, since most people don't care about them, and the result is that you end up with two major ballot choices, both of whom are nuts, because the primaries got decided by the fringes.
A lack of term limits means that members of Congress get deeply entrenched, with a result that turnover is not all that high. Why bother voting when the winner is a given anyway? Why bother voting even when the winner isn't a given if it's pretty much a given that the overall structure of power at the national level won't change? And even if that might happen, why bother voting when the other party will just filibuster the shit out of everything anyway?
Finally, the Electoral College means that the decision for the top man in government gets decided by, what, maybe 10% of the total population of the country? Presidential candidates concentrate on swing states because they're the only ones that actually count, and that makes the whole business even more fringe.
In short, it seems like the whole system is rigged to discourage moderate, sane people from wanting to participate in any meaningful way.
I know it works on me. I vote in Presidential elections and midterms, but not enthusiastically. I would never dream of joining a political party, let alone volunteering for one. I hang up on surveys, ignore campaign flyers, and never, ever donate. I haven't even written a letter to my representative in years, after realizing that all it does is generate a mail-merged form response.