In early 2016, when Senate Republicans imposed an 11-month blockade to prevent Barack Obama from filling a Supreme Court vacancy, Democrats did little to hide their outrage. In late 2016, when several GOP senators announced plans to keep that blockade going for four years — effectively saying only Republican presidents are allowed to name justices — Dems were similarly incensed.

But in 2020, the political atmosphere grew more toxic. As regular readers may recall, we saw some early hints of this last August, when Senate Republicans openly discussed the possibility of rushing through a Supreme Court nominee — at the time, a hypothetical scenario. Sen. Tim Kaine (D-Va.), a relatively moderate institutionalist not known as a partisan bomb-thrower, sent a shot across the GOP’s bow with a reference to court packing.

“If they show that they’re unwilling to respect precedent, rules and history, then they can’t feign surprise when others talk about using a statutory option that we have that’s fully constitutional in our availability,” Kaine told NBC News, referring to Senate Republicans. “I don’t want to do that. But if they act in such a way, they may push it to an inevitability.”

GOP senators, of course, acted in precisely that way, confirming a Trump nominee eight days before Election Day 2020.

Kaine wasn’t alone. In remarks on the chamber floor in October, Sen. Brian Schatz (D-Hawaii) lamented the fact that the traditional Senate “has been destroyed” through Republican recklessness on the judiciary. Soon after, Sen. Angus King, a Maine independent who caucuses with Democrats, said on CNN, “I don’t want to pack the court. I don’t want to change the number. I don’t want to have to do that. But if all of this rule breaking is taking place, what does the [GOP] majority expect?”

The day after Justice Amy Coney Barrett’s confirmation, Sen. Chris Coons (D-Del.), whom no one has ever described as a radical ideologue, conceded on The Rachel Maddow Show that it’s time for “a wide-open conversation about how do we rebalance our courts.” The Delaware Democrat added that he wants to see a “re-examining” of “the process, the results, and the consequences” surrounding what Republicans have done to the judiciary.

Senate Minority Leader Chuck Schumer (D-N.Y.) added on the Senate floor a day earlier:

“I want to be very clear with my Republican colleagues. You may win this vote. And Amy Coney Barrett may become the next Associate Justice of the Supreme Court. But you will never, never get your credibility back. And the next time the American people give Democrats a majority in this chamber, you will have forfeited the right to tell us how to run that majority. You may win this vote. But in the process you will speed the precipitous decline of faith in our institutions, our politics, the Senate and the Supreme Court. You will give an already divided and angry nation a fresh outrage, and open a wound in this chamber that may never heal. You walk a perilous road. I know you think that this will eventually blow over. But you are wrong.”

Schumer’s tone was unmistakable: he appeared to mean every word. The Democrats’ leader seemed genuinely disgusted by Republicans’ antics, and he gave every indication that the GOP should expect consequences for their actions. A few months later, Schumer became Senate majority leader, ostensibly putting himself in a position to follow through on his indignation.

But there’s been no retaliation — not because Schumer has decided to let bygones be bygones, but because some of Schumer’s members believe bipartisanship, on matters large and small, is more important than governing.

This is of renewed interest today because Senate Minority Leader Mitch McConnell (R-Ky.) said publicly that, if given the opportunity, he’ll impose another Supreme Court blockade on President Biden’s nominees.

For some, the first question may be, “Why does McConnell think he’ll get away with such brazenness?” But that gets the dynamic backwards: McConnell starts with the proposition that Democratic judicial nominations don’t count, then dares Democratic officials to do something about it.

Instead of acting, senators like Joe Manchin and Kyrsten Sinema respond by allowing the Senate Republican minority to help dictate the terms of governance, while Justice Stephen Breyer responds by pretending politics doesn’t matter at all. McConnell, naturally, puts their naivete in his pocket, and explores new ways to pursue even more aggressive maximalist tactics.

Those who decry bitter partisanship need to realize how much bitter partisanship they encourage through their passivity and tolerance of extremism.