With no significant change to the tax code, federal receipts have completely recovered from the recession, but the spending levels have remained elevated by the 700 billion "one time" stimulus spending. Put a stop to that gravy train of pork and 3/4th of the budget problems vanish immediately.
Federal receipts in 2012 are at the same dollar amount they were prior to the recession (2008 ) .
Federal receipts are not at the same percent of gdp they were prior to the recession.
Federal expenses are also higher for we are at 8% percent unemployment (and a discouraged worker base) instead of a 4 to 5% percent unemployment.
Linked below is a chart from the fed showing government federal revenue as percent of gdp of the last 65 years as well as the years and length of recessions.
This is why a theory a grand bargain or a collection of smaller bargains over an extended period of time would work. No spending cuts unless you get tax increases (or broadening the tax base, eliminate loopholes, deductions, etc); same thing in reverse no tax increases unless you get spending cuts.
It is in theory how Washington is supposed to work, neither party is going away so the only way to get something is for both sides to win or both sides to lose. Problem is due to the threat of primary challenge is more politically feasible to "lose" for it doesn't matter how much your team lose just as long as you made sure you stick it in the other team.
While social security and medicare are self sufficient currently, they won't be in the near future due to the baby boomers bump.