Five periods of history can be see here.
1. 1970-1982, the years of Nixon, Ford and Carter, where debt remained level at approximately 25%.
2. 1982-1988, the years of Reagan and his tax cuts and defense spending increases.
3. 1988-2000, the years of Bush.1 and Clinton, in which debt reached a plateau and began falling.
4. 2001-2008, the years of Bush.2, in which tax cuts stopped reducing public debt.
5. 2008-present, the years of Obama, which coincided with the Global Financial Collapse.