The most electric moment of Tuesday night’s Democratic presidential debate didn’t come during the official proceedings, which were sleepy to the point of being comatose. You might have expected sparks to fly when Sens. Elizabeth Warren (Mass.) and Bernie Sanders (I-Vt.) were asked about her allegation that in 2018, Sanders told Warren that a woman couldn’t win the presidency. But instead of baldly saying, “My opponent is lying,” Warren and Sanders offered decorous tangents.

Then the aftermath. As the no-longer-microphoned candidates departed the stage, Warren approached Sanders but stopped short of his extended hand — apparently refusing to shake it — and the two ended up in what looked like a nasty confrontation.

That was interesting because, well, personal conflict is exciting! But it mattered because most of the action in the Democratic race is the battle to become the progressive standard-bearer, since the various contenders for the moderate vote have adopted a “politely wait for Biden to collapse” strategy that won’t generate much news unless Biden obliges them.

But with Warren currently fourth in Iowa polling, her campaign has evidently decided it can’t wait. So Sanders and Warren are now directly engaged on the most frequently noted difference between the two of them: their degrees of emphasis on economic vs. identity politics.

If you watched the debate closely, however, you realized that they’re also pulling apart in other ways. Despite similar-sounding critiques of corporate power, and nearly identical Medicare-for-all plans, the two of them actually offer quite different theories of politics, government and power — and of what sort of coalition the Democrats might put together to oust President Trump from the Oval Office.

The distinction was clearest in their answers on health care, where Sanders issued yet another rousing defense of Medicare-for-all. Warren, too, is ostensibly totally for it, but when the time came to talk up her health-care agenda, she gave her Medicare-for-all plan just a glancing mention, then pivoted: “What I can do are the things I can do as president on the first day. We can cut the cost of prescription drugs. I’ll use the power that’s already given to the president to reduce the cost of insulin and EpiPens and HIV/AIDS drugs. … And I will defend the Affordable Care Act.”

That focus on small-ball executive orders rather than a sweeping legislative agenda is a sign that Warren may regret her rash commitment to Medicare-for-all. But it’s also a deeper reflection of who Warren and Sanders are as people and candidates.

Sanders remains essentially a revolutionary who wants to replace large chunks of the economy with something completely new, and will keep saying so heedless of political risks. Warren is at heart more of a cautious bureaucrat whose ideal is something like her pet project, the Consumer Financial Protection Bureau: operating by regulatory fiat, through arcane rules for very complex markets, and deliberately structured to minimize its accountability to the electorate. That’s how bureaucrats think: Why replace the system when you could place it in thrall to unelected civil servants who might redirect its activity to better ends?

In other words, Sanders thinks he can make the world a better place by rewriting the rules. Warren thinks she can make it a better place by enhancing the freedom and power of bureaucrats.

The Sanders idea might appeal to various people for various reasons: Progressives admire his purity and clarity of purpose, while even conservatives might decide that at least he clearly cares a lot about open rulemaking, democratic legitimacy and constraints on government power.

Warren’s appeal is that for all her rousing rhetoric, there will be no radical breaks with the current system. The most important changes will probably be rules tweaks that most people won’t notice or understand, even if those changes are radical in effect. And for precisely that reason, Warren is more likely to actually accomplish much of her agenda.

Her candidacy is thus perfectly pitched to technocratic professionals and moderate suburban voters, including Republicans fleeing the Trump incursion. Sanders, on the other hand, is more likely to help the party reclaim white working-class Trump voters who are fed up with the whole system, especially its professional classes.

In picking one of these candidates, progressive Democrats aren’t just choosing between a managerial revolution and the regular kind, or deciding whether they want their class war leavened with a hefty dose of identity politics. They’re also betting on which of the coalitions is most likely to defeat Trump, and deciding what sort of party the Democrats might become afterward.

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