USA is a mess. It will be Jeb vs Hillary, 2 awful potential presidents. The only candidates that have any potential to be good are Bernie Sanders and Rand Paul, and they have no chance
I think history would suggest that America has been defined as a "mess" quite often. Think slavery, Civil War, a few serious depressions, 2 world wars, vietnam, segregation (American Apartheid), legal discrimination against women (didn't have the right to vote among other things till 1920's), Watergate.... I'm not a fan of Hillary, Sanders, Paul, Bush or Trump. But i mostly dislike Trump because he's selling a lie -- back to greatness by pretending you know how to be an effective tough guy in the complex world today. I prefer a level head who at least appears trustworthy. Kasich is my choce right now -- but I am likely to change my mind.
America is a great place to live for many of us compared to much of the rest of the world. But we've always had room to get better. We are not any worse now than at many/most points in American history.