Lawyers might benefit, though. Everyone legally entitled to a payment could sue the government for damages, Adler said.

Is a brief default OK?

Another theory offered up by some Republicans is that a default of a day or so would have little impact.

But once the country breaches its promise to pay its obligations, you can't undo that. And it's likely that investors and consumers would fear it could happen again.

"There would be chaos in terms of loss of faith in the United States and its creditworthiness ... and loss of faith in our political system," Grimm said.

Do we need a debt ceiling?

Goldwein said the debt ceiling serves as a reminder of the debt we are accumulating.

But economists note that only one other industrialized nation, Denmark, has a debt ceiling. The debt ceiling, some economists say, is an anachronism and should be abolished.

"It doesn't have any purpose" because the decisions of how much to spend are made when lawmakers vote on legislation, said Robert Barbera, co-director of the Center for Financial Economics at the Johns Hopkins University.

The debt ceiling is being used to fight budget battles all over again, he said.

"It's a newfound way to be recalcitrant," he said.