Congress has tinkered with the debt ceiling, the statutory limit on amount of money the United States government is authorized to borrow to meet its legal obligations, a grand total of 78 times since 1960 - 49 times under Republican presidents and 29 times under Democratic presidents.

If the debt ceiling is exceeded, the Treasury can no longer borrow money by selling new notes and must rely instead on incoming revenue—like taxes—to pay ongoing federal government expenses. If the federal government becomes unable to make its ongoing monthly payments, federal employees are furloughed, Social Security, Medicare, and Medicaid payments stop, and federal buildings close. For example, when the debt ceiling was temporarily exceeded in 1996, the Treasury announced that it would be unable to send out Social Security checks. Clearly, the debt ceiling is not something Congress should treat as a partisan political football.

In modern history, Ronald Reagan oversaw the largest number of debt ceiling increases, and George W. Bush approved a near doubling of the borrowing cap during his two terms in office.

Here's a look at the debt ceiling under modern U.S. presidents.