I didn’t have time for a lengthy discussion of this issue, so will have to settle for some quick links of interest.
Paul Krugman and Dean Baker argue that government debt is not as big a burden on future generations as is often argued, to which Nick Rowe and Don Boudreaux respond. I would also add that Krugman acknowledges that debt owed to foreigners, and the high marginal tax rates necessary to meet interest payments on domestic or international debt, can certainly be a burden. And Krugman does not worry much, whereas I do, about the possibility that future creditors will doubt the willingness of the U.S. to raise taxes or cut spending sufficiently to meet the interest burden, the result of which could of course prove to be a huge problem.
Separately, Krugman discusses Ricardian equivalence and stimulus, on which John Cochrane and Mark Thoma offer useful comments.