The 2020 Democratic presidential primary is once again forcing the left to grapple with a tension between moderate and progressive forces. United on one side of this divide right now are Vermont senator Bernie Sanders, who has picked up where he left off in 2016, and Massachusetts senator Elizabeth Warren, who is fairly progressive on policy even as she publicly presents like a moderate. This all begs key questions about her candidacy — namely, is she radical enough? And is radicalism a help or a hindrance for someone running for president in this particular political moment?

Several other 2020 Democratic candidates on stage at Tuesday’s debate seem to think it’s the latter. The night opened with Montana governor Steve Bullock talking about “wish-list economics.” Former Maryland representative John Delaney referenced the “bad policies” of Warren and Sanders directly. And former Colorado governor John Hickenlooper called out “the front-runners at center stage” for their distance from the party’s moderate forces.

Those three candidates presented continuous challenges to Warren and Sanders as the conversation moved to a discussion of Medicare for All and immigration policy, which CNN’s moderators managed to twist into a debate about the merits of tuition-free college and free health care.

If this debate between the party’s progressive and moderate forces feels familiar, that’s because it is. The 2016 primary saw that tension strung tightly between two points on a simple (and false) binary: former Secretary of State Hillary Clinton and Sanders. A democratic socialist ideologically, Sanders was cast as the radical and used his time on the national stage in 2016 to advance policies like Medicare for All and tuition-free college. These views have since gained political legitimacy on the left, which is why more moderate candidates were so eager to attack them. Others — like South Bend, Indiana, mayor Pete Buttigieg and former Texas representative Beto O’Rourke — tried to toe the line on hybrid solutions.

According to The Washington Post, more than half of 2020 Democrats now support Medicare for All, including Warren and another front-runner, California senator Kamala Harris. Warren and Sanders are among nearly a dozen candidates who support some form of free college, according to Politico.

It is policy proposals like these that have pushed Sanders and Warren to the front of the 2020 pack. And while Sanders may be viewed as the vanguard of a political revolution, Warren also boasts well-established progressive bona fides. Described by the Post as “a Wall Street scourge,” the former Harvard University professor made her name politically following the 2008 Great Recession, first as the head of a congressional oversight panel designed to monitor the Obama-era bailout of major banks and then as part of a new federal agency overseeing the financial sector.