The debt recently passed the 15Trillion mark.

Here is the gov’t revenue:
http://www.heritage.org/budgetchartbook/federal-government-revenues
Federal Revenues Have More Than Tripled Since 1965

Overall tax revenues have risen despite a recent decline due to the recession. Congress cut income taxes and the death tax in 2001 and capital gains taxes and dividends in 2003, yet revenues continued to surge even after the tax cuts were passed.

INFLATION-ADJUSTED DOLLARS (2010): $2.15 trillion
So IF WE INSIST that -since 1000 billion = 1 trillion-  Congress agree to QUIT more spending,  use approximately 20% (400 billion per yr) to pay off the 15 T debt, and they agree; it would still take TWENTY YRS to cut the debt by eight trillion dollars.  MOREOVER,  THIS WOULD BE ONLY IF THERE WERE NO INTEREST ON THE DEBT.