"Does anyone in the class have some factual data on this?"

The only set of factual data that matters is current debt and GNP. That is, how much ya owe and your ability to pay that debt. One without the other is meaningless as a measure of anything.

If I owe ten billion and I make five billion--and all I can afford to pay towards that debt is one billion and the interest is one billion per annum, I will never retire the debt. So, match the GNP with the present national debt and then maybe there is something to argue over.