WASHINGTON — As Democratic candidates compete for the opportunity to take on President Donald Trump, the incumbent they hope to oust is more personally disliked than any of his recent predecessors, and half of voters say they’re very uncomfortable with the idea of his re-election.

But the electorate at large also expresses doubts about some of the progressive policies being backed by candidates like Bernie Sanders and Elizabeth Warren, and the party’s more moderate frontrunner — Joe Biden — also faces questions about his fitness for the job.

Those are the major findings in the latest release from the September NBC News/Wall Street Journal poll, which also shows that 46 percent of Americans give Trump credit for what they call an improving economy, the highest share of his presidency.

“The Democrats want a referendum on Trump. The GOP wants a comparative choice. And therein lies the rub,” said Democratic pollster Peter Hart, who conducted this survey with Republican pollster Bill McInturff and his firm Public Opinion Strategies.

Trump approval stable, but a record share dislike him personally

The poll found Trump’s approval rating at 45 percent among registered voters, virtually unchanged from last month and consistent with where former presidents Barack Obama and Bill Clinton stood in public approval at this point in their presidencies.

But it also showed that Trump faces historically poor personal favorability ratings, even among those who approve of the plans he has pursued in office.

A combined 69 percent of registered voters say they don’t like Trump personally, regardless of their feelings about his policy agenda. A record 50 percent say they dislike him personally and dislike his policies, while another 19 percent say that they dislike him but approve of his policies.

Just 29 percent say they like Trump personally, with 25 percent saying they also approve of his policy agenda and 4 percent saying they disapprove.

On this measure, the high degree of personal dislike for Trump differentiates him from his five most recent predecessors. Majorities of voters said they personally liked Obama, Clinton, George W. Bush, George H.W. Bush, and Ronald Reagan, even though they might disagree vigorously with their political agenda.

In fact, prior to Trump’s presidency, the highest share of voters saying they disliked the president personally — regardless of their views on his policies — was 42 percent for George W. Bush in March 2006, after Hurricane Katrina.

Voters also have higher levels of discomfort about Trump’s re-election than about his main Democratic rivals.

Half of voters — 49 percent — say they’re very uncomfortable with his 2020 candidacy. That’s compared to 41 percent who say the same for Sanders and 33 percent apiece who say the same for Biden or Warren.

But Trump also continues to benefit from the upside of the polarization of the electorate around him, commanding more enthusiasm than his Democratic competitors as well. A quarter of voters (26 percent) say they’re enthusiastic about him, while fewer say they’re enthusiastic about Warren (17 percent), Sanders (13 percent) and Biden (12 percent.)

Some progressive proposals divide Democrats and the electorate at large

Voters overall are supportive of many of the policy goals being discussed by 2020 Democratic candidates, but there are notable exceptions surrounding "Medicare-for-All," government health care for undocumented immigrants, and complete student loan forgiveness.

Among Democratic primary voters, 64 percent say they support providing government health care to undocumented immigrants, while just 36 percent of all registered voters agree.

A similar share of Democratic voters — 63 percent — support a single payer "Medicare-for-All" style plan, also backed by Warren and Sanders, that would replace the existing private insurance system. Among voters overall, just 41 percent support that idea.

And six-in-10 Democratic voters also back immediate cancellation and forgiveness of all student debt, a position shared by just 41 percent of all voters. Sanders has unveiled a plan to eliminate all $1.6 trillion in student debt, while Warren has proposed the cancellation of up to $50,000 in student debt per person, based on household income.

More moderate Democratic positions on the issues of health care and student loan forgiveness, however, have the backing of wide majorities of both Democratic voters and the general electorate.

Two-thirds of all voters — 67 percent — and 78 percent of Democrats back an optional program that would allow those under 65 to buy into Medicare just like one can currently buy in to private insurance.

A similar share of all voters — 64 percent — support a plan to forgive student debt for those who have paid 12.5% of their income every year for 15 years.

And 58 percent of all voters support a measure to provide free tuition at state colleges and universities.

While some of the most progressive Democratic proposals lack majority support, the poll also found that two of Trump’s signature plans are similarly unpopular with the voting public.

Just 43 percent of all voters support the construction of a U.S.-Mexico border wall. And exactly the same share back the elimination of the Affordable Care Act.

Voters raise concerns about Trump and Biden’s fitness for the presidency

While Biden may be the Democratic Party’s current standard-bearer for more moderate — and popular — policy proposals, a significant share of Americans in the poll say they’re losing confidence in his ability to lead the country.

A third of voters overall — 36 percent — say they’ve lost confidence in Biden in recent weeks, a time period that included a debate performance described as shaky by his critics. Just eight percent say they’ve grown more confident in him.

The same share — 36 percent — say they have become less confident in recent weeks in Trump’s ability to lead, with 17 percent saying they’ve become more confident.

Those who have lost confidence in the former vice president cited his debate performance, his age and what they say is an over-reliance on Obama’s legacy in making his own case for the job.

“Overall, I like Joe Biden a lot, but I think his performance at the debate gave me the feeling that he might be a little bit past his prime for the position,” said one male Democratic respondent from New York.

A white female Democrat from Illinois put it more bluntly.

“Basically he's an old white man who I don't think is going to help our country advance,” she said. “Because our country is not just a bunch of white people anymore.”

The NBC/WSJ poll was conducted Sept. 13-16. The margin of error for all adults is +/- 3.27 percentage points.