Should we worry about the national debt? Great post. I agree with your main point that concerns about the debt are overstated. Just a few quibbles. First, it appears that growth is slowing just at the time that the debt is exploding. The CBO estimates that within the next few years, the debt will exceed 100% of GDP for the first time in the postwar era. Thus, thanks to the recent tax cuts, the debt appears to be growing faster than the economy can grow out of it. Also, regarding Social Security, I have long been bothered by the fact that there is a cap on income for this tax at all. Social Security was sold as an insurance program, but it is essentially a cash transfer payment. As a result, I would argue that all income should be subject to the Social Security tax. Again, this would extend the solvency of the program far into the future (I believe Bernie Sanders has made this point too). Finally, while I share your admiration of Robert Reich, I would caution you that he is a lawyer, not an economist. That’s why I rely much more on people like Paul Krugman, who is actually a Nobel Prize winner.
Overall, however, excellent work!