One thing Mr. McConnell’s argument ignores is that lifting the debt limit would be necessary even if Congress didn’t spend another dime on Mr. Biden’s agenda. It must be raised because the government needs to borrow to pay all of its bills. And Republicans and Democrats alike are responsible for the gap between revenues and spending.

Mr. McConnell is also making a risky political calculation. If Senate Republicans filibuster a House bill passed Tuesday that would lift the debt ceiling, keep the government running through early December and provide funds for natural disaster recovery and Afghan refugees, then Democrats could conclude that there is little hope for bipartisan cooperation on increasing the borrowing limit. This could lead them to try to include a debt-limit increase in their $3.5 trillion spending package.

Because it would now include a must-pass measure to prevent a breach of the debt ceiling — and with the clock ticking toward default likely sometime in October — moderate Democrats would face substantial pressure to pass Mr. Biden’s sweeping bill. Republicans shouldn’t want to contribute to that agenda becoming law.