The estimable Robert Samuelson of the Washington Post had a must-read column yesterday titled “Obama’s Risky Debt.” Samuelson writes that the administration is projecting a total of $7.1 trillion in additional publicly-held debt over the next ten years, on top of $1.8 trillion for this year alone. (The Congressional Budget Office, less enthralled by the allures of Rosie Scenario, projects the additional debt will be $9.3 trillion). Today’s publicly-held debt is $6.3 trillion. Thus, using the CBO figures, in ten years the publicly-held debt will total $17.4 trillion, 270 percent of the current debt.

That’s about the same as the percentage increase in the national debt from 1930 to 1940, when the country underwent an economic crisis orders of magnitude more severe than the current one. And in 1930 the total national debt was only about 15 percent of GDP, not the 40 percent that the publicly-held debt is today. So the country was not nearly as close to being maxed out during the Great Depression as we are today, after twenty-five years of unprecedented prosperity in the country and fiscal irresponsibility in Washington.

But Samuelson does not discuss the government-held debt that will make the situation much worse by the year 2020. By far the biggest holder of federal treasury bonds is the United States Government itself ($4.2 trillion worth, as compared to $2.7 trillion held by foreigners). Most of this debt is owned by various trust funds, principally the Social Security Trust Fund. That makes the total national debt $10.5 trillion, not $6.3 trillion, 73 percent of GDP, not 40 percent.

The big problem here is that many of these trust funds will have to start dipping into their stockpiles of treasuries in order to pay their obligations in the near future. Medicare is already doing so. Social Security will begin in 2016 according to current projections, as the tide of retiring baby boomers swells.

When the trust funds need the money, they will take their treasury bonds to the Treasury and ask for it. The government will then have three means for raising the money: 1) It can make cuts in spending in other areas of the federal budget (but not to the ever-growing portion that will have to be allocated to interest on the debt, a constitutional obligation). 2) It can raise taxes substantially to bring in new revenue. Or 3) It can go into the bond market and sell still more bonds over and above the trillions of dollars’ worth it will be selling in order to finance the Obama deficits.

Congress, ever more a re-election committee for incumbents of all parties rather than a legislature, has shown scant relish for either cutting spending or raising taxes on the middle class, both of which create instant voter resentment. So it is likely to borrow still more in the bond market.

Of course one way for a government to get out from under an unsupportable debt load is to inflate its way out of it. The national debt is dollar-denominated, so a raging inflation would make it worth less as a percentage of GDP. In the inflation-ravaged 1970’s, the national debt nearly tripled in dollar terms (from $370 billion to $909 billion) but it fell as a percentage of GDP from 39 percent to 34 percent.

The Federal Reserve’s number-one job is to maintain price stability. If the Fed — despite what will be enormous pressure from politicians desperate to avoid having to take responsibility for their folly — does that job, I don’t think the present debt course will be sustainable.

How that will play out is anyone’s guess, but it will be ugly, to put it mildly. The Republican Party, however, has a great opportunity here if it has the political machismo to take advantage of the situation. The Democrats own the government and therefore they own these numbers.