For most of the last few decades, budget standoffs in Washington tended to follow the same script: Republicans threatened to block some domestic spending bill or fully shut down the government unless Democrats agreed to let the GOP own the libs with something bad like a JPMorgan giveaway, a tax break for the rich, or a draconian cut to a social program.

When Democrats controlled Congress, they never mustered the courage to respond with their own version of the same shrewd tactics. Even toward the end of the Bush era when the Iraq War was deeply unpopular, they never made a serious attempt to hold up a bloated GOP-written Pentagon bill in order to try to get their way on a progressive initiative.

But at the end of one of the worst years in recent history, it seems things are changing.

In a long overdue script-flipping move, Sen. Bernie Sanders is now moving to halt a major defense bill until and unless Senate Republican Leader Mitch McConnell allows a full vote on legislation to give millions of starving Americans $2,000 in emergency aid. That legislation passed the House yesterday over opposition from a majority of House Republicans, who tried their best to deny their own constituents much-needed aid.

Now the bill is in McConnell’s hands, and Sanders is pulling a McConnell on McConnell. He is imperiling the GOP boss’s top priority — the defense bill that authorizes pay increases for soldiers, military training, new weapons systems, while also complicating attempts to draw down troops deployed in Afghanistan. That McConnell-backed legislation could be stalled unless he agrees to Sanders’ demands and stops obstructing a progressive priority.

The Vermont independent appears ready to play hardball: He is doing his best impression of Marc Maron’s cameo in Almost Famous, effectively screaming “lock the gates!” and threatening to force Senate Republicans to remain in Washington, rather than flee while the country withers. The American Prospect reports:

Sen. Bernie Sanders (I-VT), with the backing of the Senate Democratic caucus, is prepared to make life miserable for Senate Republicans if they do not put a clean vote on the floor to increase one-time emergency payments to most Americans approved in the recent COVID relief package from $600 to $2,000.

Sanders has the procedural means at his disposal to keep the Senate in session all the way to New Year’s Day, inconveniencing Senators of both parties, particularly the incumbent Republicans from Georgia, who are in their final full week of campaigning for runoff elections on January 5….

The Senate operates on the principle of unanimous consent. It’s not impossible to get things done if one Senator objects, but it’s quite a bit slower. The majority needs to hold votes and waste time to muscle past an objecting Senator. For this reason, Sanders can prevent quick passage of the defense bill override, the only thing McConnell really wants to accomplish in the last week of the Senate session.

This ramps up pressure on McConnell to just hold a vote on the $2,000 checks. Senators don’t want to be stuck in Washington on New Year’s Eve or New Year’s Day if they can prevent it.

It is hard to predict the outcome here. The Prospect notes that McConnell can deploy some nasty countermeasures of his own that could complicate things. Meanwhile, Sanders may currently have support from liberal stalwarts such as Ed Markey — but Democrats have traditionally played the feckless Washington Generals to McConnell’s Globetrotters.

In particular, they have been loath to stand up to Republicans fraudulent accusations of sedition and their propagandistic demands to “support the troops” whenever anyone so much as questions military spending. Indeed, rank-and-file Democratic politicians in Washington typically surrender the moment any Republican waves a flag in defense of a military budget so bloated that even professional auditors cannot adequately assess its books.

Has the party suddenly found some intestinal fortitude? We’re about to find out.

Of course, up until this point, Democratic congressional leaders have embarrassed themselves, allowing Joe Biden’s ancient austerity ideology and Kamala Harris’s sudden silence to convince them to avoid driving a harder bargain with McConnell, even as Republican president Donald Trump gave them political cover to demand more.

Relegated to the sidelines as Democratic leaders were willing to accept another middle finger from McConnell, Sanders did what I saw him routinely do when I worked for him in the House 20 years ago and what he’s successfully done his entire career: He reached across the aisle to find an unlikely Republican ally (in this case Sen. Josh Hawley) to forge a left-right coalition against a corrupt center that was all too happy to tell America “let them eat cake” during an economic crisis.

Though Sanders has always been dishonestly derided by critics as an unserious policymaker and tactician, this is his patented maneuver that he’s pulled off over and over again. This time around, he is bolstered by a crop of younger House progressives who have been willing to both demand $2,000 checks and question the Pentagon budget. And his brinksmanship has already proved far more successful than anything Democratic leaders were willing to try, insofar as the Sanders-Hawley alliance helped create the political pressure for at least $600 checks rather than nothing.

No doubt, the ultimate outcome here is important — the difference between $600 and $2,000 is a make-or-break, life-and-death difference for millions of people struggling to avoid starvation, eviction and medical bankruptcy.

But Sanders’ gambit is a potential sea change moment in contemporary politics. For once, Republicans are being put in a tough spot to try to simultaneously justify rejecting a wildly popular proposal for direct domestic aid while rubber-stamping policies that allow for hundreds of billions of dollars of Pentagon spending — and they have to try to somehow rationalize that insanity during a pandemic and economic emergency.

As a chair of the Congressional Progressive Caucus in the House and then as ranking member of the Budget Committee in the Senate, Sanders has spent decades trying to indict the immorality of federal policies that expand the war machine while skimping on basic human needs. For the most part, his crusade generated eye rolls, sighs, and chuckles from the Washington media and the professional political classes of both parties.

But as Sanders now threatens to lock the gates, nobody is laughing.