This is a cautious, politic take from a Democrat who doesn’t need to worry about being challenged from the left and who’s rightly worried about progressive purity tests costing the party votes in middle America. Pelosi’s been head of the House Democrats for nearly 15 years, including during both of Obama’s landslide victories, but she’s only been Speaker for four. She’s approaching 80 and tired of being in the minority despite her own contributions over time to putting Democrats there. If returning to the majority means making sure the Democrats have a big tent, then a big tent it is. No litmus tests for her — not for abortion and not for single-payer either.

Besides, like Obama himself, too much of her legacy is wrapped up in ObamaCare’s fate for her to toss it overboard now in favor of a “Medicare for all” scheme that may yet be many years away from passing. But rest assured, single-payer will soon be a litmus test for Dems. Probably sooner than you think.

“I don’t think it’s a litmus test,” Pelosi said in an interview. “I think to support the idea that it captures is that we want to have as many people as possible, everybody, covered, and I think that’s something that we all embrace.”

Pelosi said she would like all of the ideas to be vetted and analyzed by budget scorekeepers but she believes none of them will succeed while the ACA is under attack from Republicans.

“Right now I’m protecting the Affordable Care Act,” Pelosi said. “None of these things, whether it’s Bernie’s or others can really prevail unless we protect the Affordable Care Act.”

Bernie Sanders, who’ll introduce his single-payer bill tomorrow, also denied that supporting it is a litmus test last month. But there’s a reason why so many 2020 Democratic contenders, from Elizabeth Warren to Kamala Harris to Cory Booker to Kirsten Gillibrand, have scrambled to co-sponsor it. Namely, single-payer is already popular with the Democratic rank and file. I’ve blogged various polls this year tracking Republican attitudes on single-payer but Democratic attitudes tend to get overlooked, partly because they’re already pretty consistent. In June Pew found 52 percent of Dems and leaners in favor of a single national government health-care program, up nine points in just five months. The same month, Kaiser discovered 64 percent of Democrats in favor; YouGov got nearly the same number, 63 percent, even though its question referred specifically to financing the program with taxes. Last month Quinnipiac found 67 percent(!) in favor. The Democratic majority in favor of Medicare for all appears to be growing, and no wonder. With Obama out of office and ObamaCare plagued by problems, the base and its leadership no longer have to protect O’s baby for tribal partisan reasons.

The more support there is for single-payer in the form of climbing poll numbers and big-name liberals coming out in favor, the more reinforcement for that position there’ll be. Both parties have their big-picture ideological rifts, nationalists versus conservatives on the right and progressives versus neoliberals on the left, but single-payer doesn’t lie along the left’s fault line. Most Democrats already support it! And more will support it as the Overton window moves to make it more of a mainstream position. It wouldn’t surprise me to see 80 percent of Dems in favor next year. Bernie Sanders is going to assure America tomorrow that everything they’ve heard is wrong, that Medicare for all is fiscally feasible and all that’s stopping it is political will. There will still be holdouts like Pelosi and Obama, but again, that’s mostly for legacy reasons, because they’re chained to ObamaCare. Max Baucus has already endorsed single-payer, Al Gore has endorsed it — even red-state centrists Joe Manchin and Jon Tester want to give it a look. As the drift from ObamaCare towards single-payer on the left becomes a stampede, the issue *will* increasingly become a litmus test and even Obama and Pelosi will need to climb aboard to keep their progressive bona fides intact.

There’s one more reason why this will end up as liberal orthodoxy. From Pew’s June poll:

Among Democrats aged 18-29, 66 percent support blowing up the private insurance industry and replacing it with a single government program. The future of the party is already pretty much all-in. As older Democrats age out and are replaced in the electorate by younger, more doctrinaire progressives, Medicare for all will obviously become party orthodoxy and litmus-test material. Defending the dregs of ObamaCare will become exclusively the province of … Republicans.