Despite having 17 candidates to choose from, the Democratic establishment politicos are apparently worried that the party’s 2020 presidential field seems to be winnowing to four, with Sen. Elizabeth Warren of Massachusetts showing the most momentum of those at the top. And they are right to be concerned: Warren’s base — to the extent she has one — is much weaker than President Donald Trump’s, and she faces nagging questions about her ability to inspire those other elements of the Democratic base that the party nominee will need in fall 2020.

The eventual Democratic pick will almost certainly run up against a virtual lock on support for Trump among GOP voters.

The eventual Democratic pick will almost certainly run up against a virtual lock on support for Trump among GOP voters. According to Gallup polls taken every two weeks, Trump’s support among Republicans hovers in the high 80s to low 90s. And those numbers haven’t been affected by the impeachment inquiry by House Democrats against Trump over the Ukraine whistleblower affair. Paradoxically, Trump campaign officials are using the Capitol Hill proceedings to fire up the president’s bedrock of support to an even higher degree than when he took office in January 2017. Trump’s base — broadly composed of white evangelicals, the non-college educated and rural residents — is staying loyal to him in the face of impeachment.

In one measure of this loyalty, a Public Religion Research Institute (PRRI) poll in September found that 72 percent of Republicans and Republican-leaning independents prefer Trump to be the party’s 2020 nominee over any other GOP candidate — up from 59 percent in October 2017. Another is that, according to the same poll, 37 percent of Republicans say there’s “almost nothing Trump could do” to lose their approval.

Indeed, the Republican party at present is effectively a personality cult around Trump. On the left, there's no equivalent — though it is Vermont Sen. Bernie Sanders, rather than Warren, who comes closest. Sanders has a passionate, even die-hard, following at the left end of Democratic politics that is helping him even with voters who aren’t as far left as him. The same PRRI poll found that Democrats and Democratic-leaning independents view Sanders more positively than any of his 2020 opponents. Sanders has a net favorability rating (favorable rating minus unfavorable) of 55 percent — slightly higher than Biden. Warren’s net favorability rating is down at 43 percent.

And while an Emerson poll conducted from Oct. 18-21 found former Vice President Joe Biden leading the Democratic race with the support of 27 percent of primary voters, Sanders followed closely at 25 despite having just suffered a heart attack — reflecting a resiliency among his hard-core support. Sanders also has the highest number of individual contributors of any 2020 Democratic campaign, as well as the most cash in the bank, $33.7 million to Warren’s $25.7 million.

Sanders this weekend also scored the endorsement of 30-year-old New York Rep. Alexandria Ocasio-Cortez (aka AOC), doyenne of the Democratic congressional hard left and a bellwether for that consituency’s support. Her pick demonstrates a generational span of enthusiasm for him — and the fact that, while Warren has been running hard on a strongly progressive platform designed to appeal to the energized voters on the left who love AOC, she hasn’t fully won them over.

Warren simply doesn’t engender that same sort of enthusiasm (at this point). Sure, national polls show her leading Sanders and being competitive with their main rivals Biden and, significantly further back, South Bend, Ind., Mayor Pete Buttigieg. The RealClearPolitics polling average through Oct. 23 has Warren at 22.1 percent compared to Biden at 28.7 percent. Sanders comes in third at 16.7 percent.

Warren has made serious inroads in the 2020 Democratic race with a mix of left-wing populist positions, such as a “wealth tax” and breaking up big tech companies. She’s also made inroads among moderates. But while Warren leads Sanders in the polls, her base of support remains less firm than his. She clearly has many supporters — and is continuing to gather them — but she doesn’t show evidence of the unmovable core that Trump has, and Bernie’s enduring appeal to a similar constituency underscores that.

In part, that is a reflection of her sometimes fuzzy answers about public policy issues and less-than-full devotion to far-left causes. Sanders characterized his differences with Warren in an interview with ABC as: “She is a capitalist through her bones. I’m not.”Moreover, Warren has struggled for months to say how her “Medicare for all” plan would be funded. Sanders, by contrast, has for years on his Senate website offered a detailed proposal to pay for the universal coverage concept, which aims to eliminate private health insurance.

Sanders has always seen steady support on the left and far-left. In addition to his stellar fundraising numbers, he’s turned out impressive crowdss. His New York City endorsement event with AOC drew more than 20,000 people, according to his campaign, more than attended Warren’s recent rally in the city. Moreover, he’s seen by supporters — and even grudgingly by critics — as strikingly consistent in his advocacy of causes and public policy stances.

The fact that energized support on the left hasn’t so far coalesced around Warren could perhaps avoid being a fatal problem — if she’s able to appeal to other key Democratic constituencies. But so far there is little sign of that. Warren faces ongoing challenges with black voters, crucial to claiming the Democratic nomination. She’s also coming up short with blue-collar voters, a not insignificant element of the Democratic coalition.

Democratic nominee Hillary Clinton lost to Trump in 2016 when she couldn’t replicate the astronomical voter turnout for Barack Obama because she also faced shortcomings in the base — though among different constituencies than Warren is struggling with. That largely explains how bond-rating firm Moody’s Analytics assessed in a recent report that Trump is favored to win a second term, possibly by a blowout margin, with depressed turnout on the Democratic side a main factor in its analysis. Though the report has its flaws, it’s true that a Democratic voter turnout failure could allow Trump to squeak through.

While Democrats were able to grow voter turnout among minorities, young people and college-educated whites in their 2018 midterm successes, it’s also possible that 2020 turnout could surge among non-college-educated whites — Trump’s base. That demographic did not turn out at high rates in 2018, but could do so with Trump back on the ballot.

Democrats are not doomed to lose under Warren, of course. While Warren hasn’t positioned herself as a moderate, the antipathy of many independents toward Trump leaves room for her to challenge him for swing voters. But here, too, unlikeability remains a persistent problem. Among non-Democratic voters, CNN reported, 11 percent viewed Warren favorably while 70 percent saw her unfavorably. That suggests Warren has little room for growth outside of base Democratic voters (though that’s also true for Trump vis-a-vis the GOP base.)

Warren faces ongoing challenges with black voters, crucial to claiming the Democratic nomination. She’s also coming up short with blue-collar voters.

Sanders, it’s worth noting, is making a concerted effort to win over some Trump voters, trying to show that, as a fellow economic populist, he’s their best bet. And back in 2016, about 12 percent of Sanders supporters in his primary fight against Clinton voted for Trump that November.

On the other hand, Catalist, Democratic-aligned data firm, recently estimated that voter turnout in 2020 could climb as high as 160 million people over 2016’s 138 million, fueled by the same gains in the demographics that grew in 2018 to help the Democrats in the midterms.

But that kind of turnout for Democrats is a hope, not a plan. Even though Trump’s aggregated approval rating has never escaped the 35 to 45 percent band, his supporters in that group are sticking with him. The same can’t be said for his Democratic rivals, particularly Warren. Which is why a second Trump term, despite the utter hatred and contempt of him from many on the left, could very well happen.