And, of course, a candidate who can beat President Trump — right?
After a 2018 midterm election that energized the left, perhaps the most consequential political question facing the Democratic Party is whether liberals will insist on imposing policy litmus tests on 2020 presidential hopefuls, or whether voters will rally behind the candidate most capable of defeating the president even if that Democrat is imperfect on some issues.
These dual priorities — and which one is emphasized more in the coming primary race — will help determine how the party approaches 2020. Will candidates sprint to the left on issues and risk hurting themselves with intraparty policy fights and in the general election? Or will they keep the focus squarely on Mr. Trump and possibly disappoint liberals by not being bolder on policy?
The two paths may help determine the electoral fortunes of potential left-wing candidates like Senator Bernie Sanders and more moderate ones like former Vice President Joseph R. Biden, Jr., as well as Democrats like Senator Kamala Harris and Beto O’Rourke who have a history of appealing to both liberals and moderates and drawing ire from some leftists for not being aggressive enough on policy.
Senator Elizabeth Warren showed one way of dealing with these party tensions on her first campaign swing as a presidential candidate to Iowa last weekend. Ms. Warren chose not to talk about Medicare for All, a signature issue for the ascendant left. But she seized every opportunity before overwhelmingly white audiences to highlight challenges facing people of color.
In doing so, Ms. Warren signaled to voters that she believes addressing matters of race and identity will prove as crucial to winning over Democrats as proving her bona fides on every element of economic populism.
If opposing the Iraq War was the crucial red line for Democratic candidates in 2008, many in the party believe that proving oneself as the antidote to Mr. Trump and his brand of incendiary politics will become the ultimate litmus test in 2020, more than demonstrating policy purity. Yet some activists want both: fierce resistance to Mr. Trump and unwavering fidelity to the left’s catechism of issues.
Representative Ruben Gallego of Arizona, who is eying a Senate race in 2020, said that while many voters will expect the presidential hopefuls to meet threshold tests of being progressive, the most important factors in the race are going to be an ability to inspire the party’s voters and defeat Mr. Trump.
“I don’t believe the electorate is going to be so purist that they’re going to knock somebody out because they’re not 100 percent down-the-line,” said Mr. Gallego, who added, “People are excited about candidates they think have a potential to win.”
Or, as Representative Elijah Cummings of Maryland put it: “If there’s a litmus test, it’s going to be righting the country.”
Voters, said Mr. Cummings, “are scared.”
This is exactly what alarms some on the left, who do not want the perceived threat of Mr. Trump and horse race political concerns to undercut major policy priorities.
“Fear is a useful tactic to override underlying ideological debate,” said Matt Stoller, a populist writer and former congressional aide, recalling that similar emotions about finding “electable” Democrats in the George W. Bush era led the party to embrace moderate politicians and policies to the frustration of many on the left.
As Mr. Stoller noted, much of the recent left-wing criticism against Mr. O’Rourke, the former Texas representative, was rooted in the dread that his nomination would represent a triumph of he-can-win, personality-based politics — and that he would mark a continuation rather than a break from the incremental economic policies of the last two Democratic presidents.
When many on the left listen to Mr. O’Rourke or Senator Cory Booker of New Jersey, another likely candidate, plead for a better kind of politics or healing the country after Mr. Trump, they hear an Obama-style call for stylistic change rather than a case for truly confronting entrenched power.
“We tried that and it didn’t work,” Mr. Stoller said. “And it’s pretty obvious to everybody now that it didn’t work.”
Mr. Trump’s fixation on immigration only makes it easier for a would-be candidate like Mr. O’Rourke to skirt questions about his specific policy views and instead draw broad contrasts between himself and the president on issues related to the border and the character of the country, as he has done on social media in recent days.
He and Ms. Warren are not the only potential contenders road-testing a message that spotlights their differences with the president.
“Trump is a lying populist; Democrats need an optimistic realist,” said former Gov. Terry McAuliffe of Virginia, who is considering a presidential run and trumpets his progressive record on race, gender and sexual orientation but believes that Democrats must resist the temptation of lashing the business community.
“We can’t go through this campaign demonizing folks,” Mr. McAuliffe said.
Another question ahead of 2020 is which candidate will be able to portray himself or herself most effectively as the antidote to Trump and Trumpism. Will this contrast be rendered most vividly by nominating a candidate whose platform differs from the president’s policies the most; one who can speak most articulately about changing course; or one who — through their age, gender or race — represents the starkest departure from the president?
In the midterms, Democratic primary voters rallied behind a historic number of female congressional candidates who spanned the party’s ideological gamut.
And some Democratic strategists believe that the only real issue-based tests that primary voters will put to candidates revolve around matters of race and identity.
“I don’t think you can be for stop-and-frisk in a primary,” said Cornell Belcher, a Democratic pollster, referring to the policing tactic of Michael R. Bloomberg, the former New York mayor, that critics say targets black people. “It’s less about economic issues than culture and issues of the heart.”
Yet to supporters of Mr. Sanders and some others on the left, it is folly to assume that voter hunger to defeat Mr. Trump will somehow obviate the need to offer a bold economic agenda. In their eyes, pursuing an aggressive populist agenda is essential to proving to voters that you will confront Mr. Trump.
“The party is in a different place — we need somebody to stand up and defend our core progressive values,” Ben Tulchin, Mr. Sanders’s pollster, said. “And if you’re waffling on key issues like Medicare for All, or if you lack clarity on it because you want to give yourself flexibility in governing, voters will see that.”
This moment, said Representative Pramila Jayapal of Washington, will require a candidate who sounds clarion opposition to Mr. Trump on race and gender while also embracing a full-spectrum, left-wing agenda.
“It has to be somebody who is really willing to take on race, racism and immigration, but also is willing to take on these big corporations in a way that just hasn’t happened,” said Ms. Jayapal, a rising member of the House’s Progressive Caucus.
To strategists who worked on the 2018 midterms, however, the enormous attention being paid to a handful of outspoken liberals like Representative Alexandria Ocasio-Cortez of New York misses the nonideological approach of many of the party’s successful candidates for governor and Congress.
“There wasn’t a demand among Democratic primary voters for litmus tests,” said Anna Greenberg, a Democratic pollster.
And Ms. Greenberg, who is working for former Gov. John Hickenlooper of Colorado, a possible 2020 candidate, contends that electoral viability will be more central in the coming Democratic presidential primary than in any recent election.
“Trump has framed our politics,” she said. “Everything is a reaction to Trump.”
Or, as Mr. Belcher put it: “This anger about our divisions and where our country is going will be front and center — and the candidate who can speak to this division and be a direct contrast to Trump is going to do really well.”