Repugs
Yes, debt as a percentage of GDP is irrelevant. The best way of measuring debt is to look at how much you owe, and see if it is more, or less, than the year prior. If it is more... that's bad. If it is less, that's good.
Debt as a percentage of GDP was created as a method for justifying over spending, by making a number that can go down, while the actual debt goes up.
As long as people are willing to hold on to that irrelevant statistical number, congress will have freedom to over spend.
That is why Repugs are Repugs. If they stood up for what they are supposed to believe, I would dignify them with their correct name.
But honestly I don't completely blame them. The 95 budget battle was over this specific issue. They wanted to balance the budget, but instead they were creamed in the press and by ignorant voters, over trying to be fiscally responsible. So years later, they have the chance to try it again and... no I don't think so, got nailed last time.
See the real sorry excuse for an answer is, we the people. It's us. The public doesn't want a balanced budget. We want Social Security, Medicare, Medicaid, Public Housing, Food stamps, Welfare, Grants for Medical Research, Student Loans, Alternative Fuel Research and on and on and on... And we don't want someone to tell us we can't afford it, because everyone deserves health care... we don't want to hear money doesn't grown on trees behind the capital building. We really are a pathetic people 
