This is because GDP dropped, hence tax revenues dropped, hence debt went up. None of which are related to his policies. It's not because he started some big spending program. Some relevent links:
http://krugman.blogs.nytimes.com/2010/08/03/hey-small-spende... http://krugman.blogs.nytimes.com/2010/10/15/big-spender-upda...