Before the Nazi Party came to power in Germany, you did not have to have a Ph.D. degree to figure out that their party was populated primarily by a lot of people who had a lot of pent-up and suppressed anger.
The same thing is happening today in the United States. The Tea Party is the new Nazi Party. They are full of anger. They are racists who dislike blacks, Hispanic immigrants and anyone who has a “socialist” agenda. The idea of people helping people is anathema to them.
Their primary method of action is confrontation. America always has had a need to confront those people who have been officially designated as “enemies.” In the 1950's it was the evil communists. Today it is the Muslims abroad and liberals at home.
Hitler and his Nazis went about invading half a dozen countries in Europe and unleashing a holocaust against those they hated. Today, the U.S. has invaded Iraq, Afghanistan, Pakistan, and would like to invade Libya.
At home, the U.S. is in a downward spiral of economic and social decline. That helps to feed the anger of those who would like to restore the U.S. to the position it had after World War Two.
The confrontation in Wisconsin is a manifestation of the environment of hate that today pervades our society.