From what I've seen, welfare spending has been roughly flat (say a 5-10 yr moving average) since the Nixon/Ford era, and tracks well with unemployment rate (Fig 2). So spending spikes during recessions and drops during better times. And this has happened through Dem and Rep administrations as well as Dem and Rep Congresses. If Fig 1 is close to correct for 2011 spending (it may not be), welfare spending is near a local maximum, not terribly unusual, given the depth of the recent recession and financial crisis.
Fig 1: Federal welfare spending as a fraction of GDP (numbers beyond 2010 are projections)
Fig 2: US unemployment rate