President Obama has returned to a theme he used effectively during the 2008 campaign: politics is too divisive; name-calling isn't helpful; labeling people doesn't solve problems. In his commencement address to University of Michigan graduates last Saturday, the president said, "We've got politicians calling each other all sorts of unflattering names. Pundits and talking heads shout at each other. The media tends to play up every hint of conflict, because it makes for a sexier story -- which means anyone interested in getting coverage feels compelled to make the most outrageous comments." All true. In our 2008 book, "Common Ground:...