How about debt servicing Jay?
Debt to GDP is only one metric - interest expenses vs taxation revenue a better one IMO. Any increase in borrowing costs will crush the US budget (and other sovereigns for that matter). Also - ageing population hurting now. Even the GAO forecast that Medicare/Medicaid etc would grow at 2-3 times the pace of GDP between 2007-2032. They are unprepared IMO.
Debt to GDP ratio is returning to roughly pre-financial crisis levels. I don't think debt servicing will impose a significant drag on GDP unless/until Medicare or Social Security becomes a major burden when all the baby boomers are done working. If nothing changes, that won't be for another 30 years or so.