There is a two year lag between election and presidents being responsible for all of the budget. Bush was appointed by the Supreme Court following the 2000 election and took office in 2001 under a budget of the House and Clinton administration. Similarly Obama took office in 2009 but the 2009 budget was Bush's and Congress's final act. I urged Obama to have nothing to do with it, the FDR policy, but begin a clean sweep after he took office as Republican's would claim his support for the proposals and helping Bush pass it would let them claim it was his. That is exactly what they have done.
Here is the share of all government USA spending as percent of GDP. 2010 to 2013 is under Obama's leadership.