There seem to be two kinds of Republicans: those who think that the full faith and credit of the United States can be the subject of political experimentation, and sensible ones.

Treasury Secretary Steven Mnuchin fits in the latter category. He has repeatedly called upon the Republican-controlled Congress to pass an increase in the statutory debt limit, with no policy strings attached, so that the U.S. government may continue borrowing past the current, already expired ceiling of $20 trillion – and pay all of its obligations on time. The stability of the financial system, domestic and international, depends on preserving the “risk-free” status of U.S. debt, earned over centuries. A failure to raise the debt limit would imperil this status.

Lawmakers, however, have so far declined to follow Mnuchin’s advice. Mnuchin says the drop-dead date for legislative action is Sept. 29 – giving Congress just 12 working days after it returns from August recess.

Mnuchin is getting no help from Mick Mulvaney, director of the Office of Management and Budget. On Sunday, Mulvaney answered “yes” when CNN’s Jake Tapper asked if the White House policy was to insist that Congress not vote on any other legislation, including the debt ceiling, before trying once again to repeal Obamacare.

This seemed to reopen a rift that first appeared in the spring, when Mulvaney spoke of making a debt-limit extension contingent on spending cuts – only to be publicly contradicted by Mnuchin, apparently with President Trump’s authorization. Now, who knows?

Trump’s chief of staff, John Kelly, got his new job with instructions to impose order on the chaos that reigns at 1600 Pennsylvania Ave. We can’t think of a better place to start than by bringing everyone in the administration into line, starting with the man at the top, behind Mnuchin’s position on the debt ceiling. The hour is getting late, and the stakes are immense.