On the sixth floor of a sleek office building here, more than 150 techies are quietly peeling back the layers of your life. They know what you read and where you shop, what kind of work you do and who you count as friends. They also know who your mother voted for in the last election. The depth and breadth of the Obama campaign’s 2012 digital operation — from data mining to online organizing — reaches so far beyond anything politics has ever seen, experts maintain, that it could impact the outcome of a close presidential election. It makes the...
