There was never a surplus, the national debt has increased every month for 30 years. OK, a couple of months it didn't, probably including August and September of this year.
The 'surplus' is due to bogus accounting, where they treat the US bonds bought for the SS 'trust fund' as an asset, but don't count the spending of the $ as a liability.
That's the difference between the "Total Public Debt" and the "Total Debt". The latter includes the Intergovernmental Debt (such as the automatic "investment" of Social Security Trust Fund assets in non-marketable Treasury instruments, while the former only includes instruments sold publicly.
The much-ballyhooed "surplus" that Clinton had was in fact a small decline in the Total Public Debt while the Total Debt never declined (on an annual basis, at least) during his presidency.
Total Debt is what really matters. You're not getting ahead when your car, mortgage, and credit card debt have declined by $20,000 but your 401k loan has increased by $25,000. Your Total Debt has increased by $5,000. (Not a perfect analogy because of interest rate differentials, but the closest analogy I could come up with for a person where he "owes it to himself".)
While it's true that you could actually run a surplus and Social Security surpluses would still be "invested", increasing the Intergovernmental Debt, those funds would then retire Public Debt. This, along with debt retired by the actual surplus, would result in the Public Debt falling more rapidly than the Intergovernmental Debt increased and would lead to a declining Total Debt.
So, if the Total Debt didn't fall, there was no real surplus.