GOP leaders have insisted that Democrats lift the cap on government borrowing without Republican votes, by using the same budgetary move that’s helping them take up a mammoth social spending plan as soon as this week. But that’s an untested play, one that could put the whole package — which is already wobbling amid intraparty disputes — at risk.

It’s a lengthy maneuver, too: Experts and congressional aides estimate that adding the debt limit to Democrats’ party-line spending bill could take about two weeks, requiring revisions to the budget measure that the party deployed to steer it past a Senate GOP blockade. Two weeks is an eternity, given that Congress could slam into a debt wall in as little as three to six weeks, according to a new estimate from the Bipartisan Policy Center — which helps explain why Democratic leaders aren’t seriously entertaining the idea of ripping up their spending bill, for now.

Of course, Democrats may still be forced to ready that unsavory off-ramp, if Republicans keep to their vow to deny President Joe Biden’s party the votes on their strategy and the global economy moves closer to a tempest.

Senate Budget Chair Bernie Sanders insisted last week that there is “no backup plan.”