A major sequel to last week’s post noting that Kyrsten Sinema has also declared her opposition to ending the filibuster if Democrats end up in the Senate majority in 2021. The hole is getting deeper for Elizabeth Warren and Bernie Sanders in trying to get the most ambitious parts of their agenda passed, starting of course with Medicare for All. If the filibuster remains intact then Senate Republicans will be able to block nearly anything Chuck Schumer puts on the floor with just 41 votes. To end the filibuster, Schumer would need 50 votes (with Warren’s VP available to cast the tiebreaker). But Democrats are already at a three-seat disadvantage in the Senate, which means that if Sinema, Joe Manchin, and Jon Tester are true to their words Dems would need a *net* gain of six Senate seats next fall to have a shot at making that happen.

Let me stress: A net gain. Doug Jones will likely lose in Alabama so Democrats would somehow need to flip no fewer than seven Republican-held seats in order to make Sinema, Manchin, and Tester expendable on the filibuster vote. And even in that best-case scenario, all seven freshmen would need to be so gung ho about passing a socialist agenda that they’d be willing to overturn the filibuster too. How likely is that? How likely is it that a newly elected senator from a swing state — or even a red state — would opt to go nuclear in support of ending private health insurance in America on basically their first day on the job?

If Warren’s serious about Medicare for All, which is unlikely, she needs the sort of landslide next fall that will intimidate Sinema et al. into believing that American voters will stand for nothing less going forward than socialism in full flower. That’s also unlikely.

“I’ve always been there. That’s been my position from day one,” Manchin tells National Review. Are there any circumstances where Manchin could see himself voting to eliminate the 60-vote requirement for legislation? “Never,” Manchin replied. “Nope, I’m sitting in Bob Byrd’s seat. Just read his history.”

“I don’t want to see the Senate become the House,” Montana senator Jon Tester tells National Review when asked about eliminating the legislative filibuster. Asked if he could imagine any circumstances where he would change his mind about the filibuster, Tester says: “Nope.”

It’s not just Manchin and Tester, in fact. Bob Casey of Pennsylvania and Jacky Rosen of Nevada also told NRO’s John McCormack that they oppose ending the filibuster. So conceivably Democrats would need nine picks-ups next fall. Or eight plus the surprise reelection of Jones in Alabama.

Is there a scenario where Democrats might oppose nuking the filibuster *initially* and then come around on it, though? That’s more realistic. And some are already talking it up:

“I can only imagine myself being willing to do that where persistent Republican obstruction prevented us from making progress on the core issues facing our country for a long period of time,” says Delaware senator Chris Coons. “Not the first day, not the second day. Not the first months.”

The more comprehensively McConnell roadblocks Warren’s agenda, the higher the pressure will get from the left on Sinema and the rest not to let Republicans paralyze Democrats. And that pressure will come quickly: Lefties understand that the out-party tends to do well in midterms after a new president is elected, meaning that Warren might have as little as two years to get something through before the GOP controls the Senate again. Potentially Senate moderates from both parties could use that dynamic to their advantage. Collins, Murkowski, and Romney might cite the growing likelihood of Dems ending the filibuster as reason to compromise with them on legislation, alleging that without compromise socialism will ultimately be rammed through. Sinema, Manchin, and Tester might compromise in return and use their leverage over the filibuster to get Warren to agree to more moderate reforms. The White House might be offered a take-it-or-leave-it: Either the centrist agenda passes or Warren can endure a total Republican roadblock for four years.

Does the math work here, though? Assume a 51/49 Democratic Senate. Republican moderates like Romney would need to find nine votes in their caucus to join with Democrats in moving a centrist agenda. I don’t think there are nine moderate Republicans in the Senate. Even if there are, we’re presuming unanimity on the Democratic side in support of a centrist agenda simply in the interest of getting something passed. I don’t see Bernie joining that effort, among others; lefties would howl that centrist reforms must be obstructed lest they pass and become a new status quo with which the public would quickly become comfortable. Socialism might stall for another decade. So we may see Senate paralysis despite the best efforts of centrists on both sides.

In which case Sinema, Manchin, and Tester will face a very hard choice on how long they want to enable McConnell. I believe them when they say they don’t want to end the filibuster. I don’t quite believe that they’d go on refusing to end the filibuster if we end up in another years-long stalemate. Especially if Warren and Schumer skip Medicare for All temporarily and start out offering highly popular legislation — like universal background checks — instead. There are likely to be 41 Republican votes to filibuster that despite the fact that it polls at 90 percent across the country. Is Sinema, from Gabby Giffords’s home state and with Giffords’s pro-gun-control husband possibly serving alongside her in the Senate, prepared to go to the mat on the filibuster so that 41 Republicans can hold up universal background checks for another half-decade?

In fairness to Warren, she’s not the only Democratic candidate who’s waaaaaay too optimistic about the chances of her agenda being passed. If Warren is too rosy about the likelihood of Dems ending the filibuster, Grandpa Joe is too rosy about the likelihood of Republicans working with him:

There’ll be no “epiphany,” my dude. The post-Trump GOP will not suddenly redefine itself as a band of can-do problem-solvers who’ll work with a friendly Democratic president. Obama too once entertained the claim that the “fever” on the right would break if he was reelected in 2012, with obstructionism giving way to dealmaking. I doubt he really believed that; it sounds like a canned answer to reassure concerned fans that his agenda would advance despite ferocious Republican opposition if only they pulled the lever for him one more time. (It’s not that different from Warren touting M4A knowing that she doesn’t have the numbers to end the filibuster. Just vote for me and everything will magically change!) I get the sense from Biden that he really believes it, though, which is so weird for an Obama White House veteran. The GOP won’t have an epiphany on compromise after Trump; if anything, the ideological vacuum on the right will be so powerful (for awhile) that obstruction will necessarily fill it as a placeholder until something more substantive replaces it. One might even argue that a lefty populist agenda like Warren’s stands a (slightly) better chance of a Republican buy-in than Biden’s does since righty populists overlap with progressive ones on certain issues (e.g., reducing the power of Big Tech). Does anyone really buy this line from Biden?