Democrats accused advocacy groups allied with Republicans of "stealing our democracy" in a new national television ad released Sunday. The Democratic Party upped its ante against the U.S. Chamber of Commerce and American Crossroads, a conservative advocacy group founded by prominent Republicans Karl Rove and Ed Gillespie, with the new ad. "Karl Rove, Ed Gillespie: They're Bush cronies. The U.S. Chamber of Commerce: They're shills for big business," the Democratic National...