Whether or not to impeach President Trump has become the new litmus test for the 2020 Democratic presidential field, with two high-profile progressive candidates coming out in favor of launching impeachment proceedings in the five days since Special Counsel Robert Mueller’s report became public.

The growing prominence of the impeachment issue was abundantly clear during a marathon night of CNN town halls from New Hampshire on Monday, during which each of the five candidates who appeared was peppered with questions about his or her stance soon after taking the stage.

Sens. Elizabeth Warren (D-MA) and Kamala Harris (D-CA) cited Mueller’s findings, most notably the special counsel’s explicit refusal to clear Trump of obstruction of justice, as grounds enough to impeach him. But rivals like Sen. Bernie Sanders (I-VT) raised the possibility that the effort to remove Trump could backfire politically.

The divide apparent on the presidential town hall stage Monday reflects the divide in Congress, where Democrats are pulled in opposite directions by a progressive wing—which believes impeachment is a must-pass integrity test for its leaders—and a moderate wing that worries a push to remove the president could cost them Congress and keep Trump in the White House another four years.

During her appearance, Harris made news by announcing that she supports initiating impeachment proceedings. “I believe Congress should take the steps towards impeachment,” she said. “ I think we have very good reason to believe that there is an investigation that has been conducted which has produced evidence that tells us that this president and his administration engaged in obstruction of justice.”

Harris hedged a bit by stating she is a “realist,” noting that impeachment is dead on arrival in the Republican-held Senate. “We have to be realistic about what might be the end result, but that doesn’t mean the process should not take hold.”

But the first candidate to come out in favor of impeachment, Warren, forcefully reiterated her call for Democrats to pursue it no matter what the political realities are. If lawmakers want to be on record upholding the president’s conduct, said Warren, “then they should have to take that vote and live with it for the rest of their lives.”

“There is no political inconvenience exception to the United States Constitution,” said Warren to applause. “This is not about politics. This is about principle. This is about what kind of a democracy we have.”

Other candidates acknowledged the gravity of Mueller’s findings but tossed varying degrees of cold water on Warren’s heated impeachment pitch—most notably Sanders.

“If for the next year, year and a half, going right into the heart of the election, all that the Congress is talking about is impeaching Trump and Trump, Trump, Trump, and Mueller, Mueller, Mueller, and we’re not talking about health care, we’re not talking about raising the minimum wage to a living wage, we’re not talking about combating climate change, we’re not talking about sexism and racism and homophobia, and all of the issues that concern ordinary Americans, what I worry about is that works to Trump’s advantage,” said Sanders.

“At the end of the day, what is most important to me is to see that Donald Trump is not re-elected president, and I intend to do everything I can to make sure that doesn’t happen,” he added.

Sen. Amy Klobuchar (D-MN) argued Trump should be held accountable for what Mueller found but said the Senate is the jury for impeachment, “so I am not going to predispose things.”

Pete Buttigieg, who filled the final town hall slot, tried to offer a middle ground. “He’s made it pretty clear that he deserves impeachment,” said the mayor of South Bend, Indiana, of Trump. But Buttigieg said he views his task in 2020 as sending Trumpism to the “dustbin of history” and argued “there’s no more decisive way to do that… than to have just an absolute thumping at the ballot box for what that represents.”

Earlier on Monday, Democrats’ impeachment dilemma played out among lawmakers during a conference call convened by Speaker Nancy Pelosi (D-CA) for House members to debate the post-Mueller path forward.

On Friday, Pelosi’s deputy, Majority Leader Steny Hoyer (D-MD), drew criticism for saying Democrats shouldn’t pursue impeachment, while progressive upstarts like Rep. Alexandria Ocasio-Cortez (D-NY) took the Mueller report as reason to sign onto impeachment efforts.

Those divisions persisted on the phone call, with some Democrats favoring moving toward impeachment, purple-district freshmen raising concerns about the political ramifications, and others pushing the new middle ground of a resolution to formally censure the president, reported The New York Times.

One Democratic lawmaker told The Daily Beast that most of the caucus was in favor of the wait-and-see approach. “The loudest voices in the caucus,” they said, “don’t reflect where most of us are.”