When the federal government’s spending obligations exceed its tax revenue, the Treasury Department fills the gap by selling bonds. But Treasury’s ability to sell bonds is limited by the statutory debt ceiling, which needs to be periodically raised or suspended in order to allow the normal functioning of government to continue. If it isn’t, the government will fail to meet some of its legal obligations — including its obligation to pay the holders of older debt.

This is a clumsy institutional design that has a weird history and was for a time the subject of some obnoxious political theater with no real significance. Then, during Barack Obama’s presidency, House Republicans irresponsibly began to wield the debt ceiling as a weapon to try to force policy concessions and damage the economic recovery. It faded as an issue during Obama’s second term, and under Donald Trump, it again became a routine piece of legislative arcana that was simply dispensed with on …