Barack Obama has launched his first spot since becoming the presumptive Democratic nominee. It's a biographical spot that plays up his modest upbringing and, notably, says nothing at all about John McCain. Another striking thing about the ad is the predominance of solid, Middle American-looking white people, including his mom and grandparents -- which is a smart move considering many people outside of Democratic primary voters have heard so many ridiculous rumors about Obama's background that they might not even know he's half white. (Of course such a thing shouldn't matter ... but of course such a thing does matter.) All those white people also might have something to do with where the ad is running: Alaska, Colorado, Florida, Georgia, Iowa, Indiana, Michigan, Missouri, Montana, Nevada, New Hampshire, New Mexico, North Carolina, North Dakota, Ohio, Pennsylvania, Wisconsin and Virginia. This choice of states also provides a clue to what will be considered this year's "battleground" contests.