Well, here's some disconcerting news as the nation prepares for the Fourth of July, normally a benign and pleasant holiday with good eats, sparkling fireworks and a general sense of well being. That may not be the case this year. Cultural and political divides are taking a genuine toll on the nation, along with a creeping sense that something is going wrong within the United States of America. So says a poll released Thursday by the University of Chicago's Institute of Politics.