This is a preposterous comparison to begin with, for two reasons:
In good economic times, presidents have paid down the national debt. In 1834 Jackson paid it off entirely. In fact, most presidents in the 1800s paid it down, as did Harding and Coolidge in the 1920s. And from 1946 to 1981 the debt was consistently reduced in real terms, though not in nominal terms. It's unfair to add together all those positive and negative contributions, then compare them to a president who inherited two wars, hemorrhagic tax cuts, and a massive recession.
From 1800 to today, the dollar has inflated by 1270%. Comparing nominal dollar values makes past debt increases look insignificant, even if you isolate them from debt reductions.
Yet even on those incredibly skewed grounds the comparison is false.
FactCheck.org has a detailed analysis, based on the same source Rachel McGilray used (Debt to the Penny). Here's an excerpt:
And it’s also untrue — as claimed in a graphic widely circulated by email and in social media postings — that the debt has increased more under Obama than under all previous 43 presidents combined. In fact, as of Jan. 31, 2012, the rise under Obama had yet to surpass the rise under his predecessor, George W. Bush.
The figures in that graphic are pure fabrications, as anyone can easily confirm by plugging Obama’s inauguration date — Jan. 20, 2009 — in the Treasury Department’s handy “debt to the penny” website. That shows the nation’s total debt stood at $10.6 trillion on the day Obama took office (not $6.3 trillion), and it had increased to nearly $15.4 trillion by the end of January 2012 — a rise of more than $4.7 trillion in just over three years (not $6.5 trillion).
That’s a huge increase to be sure — 44.5 percent. And the Congressional Budget Office now projects that it will grow to more than $16 trillion by the end of the current fiscal year on Sept. 30. At that point, the debt will have increased by more dollars in Obama’s first four years than it did in George W. Bush’s entire eight-year tenure, when it rose by $4.9 trillion. The rise under Obama would then be the biggest dollar increase for any [single] president in U.S. history.
That's still nominal dollars. Let's compare the total debt increases of the last five presidents in present dollars:
Obama: $4.89 T
Bush II: $5.73 T ($2.40 T in first term, $3.33 T in second)
Clinton: $2.21 T
Bush I: $2.54 T
Reagan: $3.82 T
To adjust for inflation, I used the average CPI values from the presidents' terms. Notably, under Obama the total public debt has increased by 38% in real terms, versus 54% under Bush II and 108% under Reagan.
Obama has not “accepted more debt than all previous U.S. presidents combined,” or even half that. Nor has he raised the total debt more than the previous four presidents, or even half that. But during his tenure, the total debt has risen faster than at any other point in U.S. history.
Bush II holds the record for raising the debt more than any other single president. Obama will break this record in nominal terms at the end of the fiscal year and in real terms at the end of his term.
Reagan is the only president out of the past five to have “accepted more debt than all previous U.S. presidents combined.” In real terms, he doubled the total debt. In nominal terms, he almost tripled it.
Before that, FDR raised the total debt in real terms almost sixfold and in nominal terms eightfold. Lincoln raised it in real terms 20-fold and in nominal terms 30-fold.