In 1981, when Reagan rode into Washington with his supply siders, the debt had been going down relative to national income for 35 years. But he said he'd do much better — he'd reduce its dollar value, and fast. Well, let's go easy on the old guy. He had no idea.
But he should have at least kept if from going up relative to national income. But no. He sent it up so fast that it went from 33% to 68% of national income by the time G.H.W. Bush left office. So zFacts worked out what the debt would have been on Sept. 30, 2010, if Reagan and the Bushes had just kept the debt from going up relative to national income when they were in office. The answer is $9.2 trillion.
Of course that debt is still earning interest, so its getting bigger all the time. That's why the Republican National Debt clock is still clicking away. More info here