Sarahbeth Maney/The New York Times / Senate Minority Leader Mitch McConnell of Kentucky speaks about the debt limit at a news conference at the Capitol in Washington, Sept. 22, 2021. McConnell is encouraging Democrats to raise the debt ceiling and telling Republicans to vote no against the infrastructure bill.

John Thune of South Dakota, the second-ranking Senate Republican, says that "the debt limit needs to be increased." He also says Republicans are not going to vote for it. He thinks the Democrats can and should do it on their own. This stance makes political sense, but no other kind, which suggests that the debt limit should be repealed.

The conventional view, which Thune clearly accepts, is that failing to raise the debt limit would cause the federal government to default on its obligations in short order, with large economic costs. Without the increase, money to pay the government's bills could run out in October.

But if you look at the issue from the perspective of Thune and the other Republicans, you can see why Democratic efforts to shame them into voting to raise the debt limit are failing.

There is a long bipartisan tradition of opposition parties inveighing against the irresponsibility of the party in power for debt-limit increases.

"America has a debt problem and a failure of leadership," said Sen. Barack Obama in 2006. "Americans deserve better." Sen. Joe Biden voted with him as Republicans, then in the majority, raised it on their own. When Obama and Biden became president and vice president, their view of which stance on the debt ceiling was responsible changed dramatically.

There is also a tradition of bipartisan deals that enable an increase in the debt limit. In 2011, Republicans controlled the House and Democrats the Senate and White House. They negotiated an increase in the debt limit paired with a reduction in the growth of federal spending. In 2019, with President Donald Trump in office, both parties were in a freer-spending mood. They agreed on spending increases and raised the debt limit.

From Thune's point of view, what's on offer today looks a lot worse. Republicans are being asked to give up the opportunity to take shots at Democrats over the debt-limit increase without getting any policy victories in return. The Democratic leadership in Congress and the White House is seeking to enact $3.5 trillion in spending increases and nearly as much in tax increases on a party-line vote. That's after passing a $1.9 trillion spending bill, also on party lines, in March.

If Republican senators vote to increase the debt limit, they will have to explain to their supporters why they are making it easier for Democrats to accomplish their budget goals and failing to capitalize on its political downsides.

The potential political cost of the Republicans' current stance — you guys raise the debt limit without our help — is that it makes them look irresponsible. But voters have not held debt brinkmanship against the parties that engage in it. Democrats won a landslide victory in the 2006 midterms after Biden and Obama voted to let the government hit the debt ceiling. Republicans brought on a government shutdown and flirted with a debt default in 2013, and were rewarded with their own landslide in the 2014 midterms.

I used to think the debt limit served a good purpose. Congress and the president make spending and tax decisions that are not connected to each other, and let the largest spending programs, such as Medicare and Social Security, grow on autopilot. Debt-limit votes are moments when political leaders can take responsibility for the consequences. They can in principle yield reforms that restrain the growth of that debt.

But the 2011 deal was probably the best case of such reforms actually happening, and looking back a decade later it does not appear to have made a lasting difference in the trajectory of the federal debt. The debt limit, that is, hasn't actually limited the debt.

Stein's Law, named for the economist Herbert Stein, holds that unsustainable trends will eventually stop. Debt-limit game-playing is one of them. One of these days we will either get rid of the limit, or we really will have a default.