I can only say that I was in D.C. in March with my family during the time when the Tea Party had decended upon Capitol Hill in droves to protest the coming vote on health care.
You'll remember that there were many allegations that these folks hurled the n word about, and even spat on some congressmen as they walked from the Capitol building to their offices. This has never been proven despite a reward of 100,000 dollars for any video of such action.
The day after the demonstrations, a park police officer told me that the crowd had been exceptionally well behaved, and that they had left behind not so much as a gum wrapper on the Capitol grounds. He also said that after the Obama Inaugural, it took 24 hours and a crew of end loaders to remove the trash.
This ought to tell anyone in doubt all they need to know!