12 governmental bodies for 170 million people-- semi-similar to what our local governments attempt to do, but with the overreaching hand of the federal government looming above. Look at the pot laws in Washington and Colorado. Or the immigration laws in Arizona--laws that absolutely wouldn't have a chance in hell of passing in, say,New England. The tricky part is instituting something like universal health care (which we mangled, and replaced with universal health insurance... because lingering Cold War paranoia about any state mandates are present enough to make some portions of the country grab their guns and hole up in their fortified compounds....) when what would work for one region or state isn't going to fly with the populace of another--Massachusetts and North Dakota,for example.
That, coupled with the fact that even though Americans aren't really taught history, we all "know" that our country was founded in defiance of taxes and government control, ties the Feds hands on a handful of issues--because so much of a representative's job is getting re-elected, they can't afford to really make waves that would help people (see: Obamacare, and even that almost sank him).
As for our impact on the globe... American Exceptionalism, baby! Now give us all your sexy ladies and all your natural resources.
