It is the second graph which we need to be concerned about: the graph of debt vs. GDP. The first graph does not factor in inflation. Though the national debt appears to increase exponentially, the value of the dollar is also decreasing exponentially.
Here is another view of Tadpole's second graph:
I think these graphs make the effects of cutting taxes without cutting spending very clear.
I don't like Fair Tax, as it's never shown to be fair, IMHO, but I certainly agree we need to adopt a tax plan that does not allow offshore accounts or any corporation transferring to Dubai to take tax dollars with it...