Of all the progress Democrats have made since the 2016 elections, perhaps the most exciting “win” is the surfeit of bold and ambitious policy ideas to make America more egalitarian and sustainable.

Whether they’re talking Medicare For All, universal income programs or a Green New Deal, the Democrats are aiming high and coalescing around a platform that speaks to the hopes and fears of voters who’ve felt marginalized by America’s mostly white and wealthy leadership class.

Who Democratic voters choose to be their standard-bearer in the 2020 election remains to be seen. But whoever wins the nomination will have successfully convinced voters that their resume and rhetoric are proof that they are the most committed to enacting the new platform of the left.

But what if a commitment to progressive policies and ideals is the wrong place to be assessing 2020 candidates? What if the true test of each candidate’s commitment to universal health care and decarbonization isn’t how long they’ve supported these ideas, but how far they’re willing to go in fighting for them?

This was raised by New Yorker staff writer Osita Nwanevu the other day, when he took to Twitter and tossed out a simple question for Democratic voters, activists, pundits and elected officials: Why aren’t the Democrats talking about killing the filibuster?

For those who need a refresher, the filibuster is an obstruction motion that can be taken by a minority of senators to stall debate on a piece of legislation or a nominee for a high-level office. When the filibuster is invoked, 60 Senate votes are required to overrule it. (The 60-vote rule was also in effect for judicial appointments, until 2013, when then-Senate Majority Leader Harry Reid amended the rules to allow a simple majority vote to confirm judicial appointments — the so-called "nuclear option.") Even if the Democrats win a supermajority in 2020, the filibuster could be the death of every legislative idea that the Democrats aspire to ratify. Why? Because whether or not they take control of the Senate, the Democrats are extremely unlikely to hold a whopping 60 seats.

Before anyone shouts “Blue Wave 2020!” remember that the Senate apportions two seats to every state, which benefits low-population rural states. These states generally vote red, which is exactly what happened in the recent midterms. And given that those midterms were the first big “test” of whether Donald Trump’s conduct in office would have negative ripple effects for Republican members of Congress, the verdict is in: Almost every Republican senator was re-elected, and Republicans will now hold 53 seats in the Senate (up from 51).