this article "the national debt graph by president" that explains how the debt got where it is [View all]
according to the writer -
So we will ask, What if Reagan and the Bushes had balanced their own budgets? And what if Clinton and Obama had taxed the same and spent the same as they actually did?
The answer is that the National Debt would now be lower by $13.5 trillion! So thats the Republican National Debt according to their own standard of balanced budgets.
Its quite easy to check these calculations (see this spreadsheet). They go like this: When Reagan took office the debt was $1 trillion. When he left it was $2.86 trillion. So $1.86 trillion for him. Then Bush-I added $1.55 trillion. Total so far: $3.4 trillion. Then Clinton took over.
Now the national debt is like a mortgage, and so the bigger it is, the more interest must be paid on it. Without the extra Reagan-Bush $3.4 trillion, there would have been a few hundred billion less in interest on the debt every year under Clinton. That interest adds another $2.3 trillion to the Reagan-Bush debt. Then Bush II increased it by $6.1 trillion to $11.8 trillion. And interest on that has been increasing the debt under Obama. The total Reagan-Bushes debt is now $13.5 trillion.

http://zfacts.com/p/318.html
there's more at the link --