Sen. Bernie Sanders will offer a robust defense of his democratic socialist political philosophy Wednesday amid growing clamor from centrist Democrats that some of his proposals on health care and climate change play into the hands of President Trump.

The defense will be offered in a speech at George Washington University in Washington, D.C., that has been billed by the Sanders campaign as an opportunity for the White House hopeful to explain democratic socialism in its historical context.

Sanders – and Democrats writ large – are facing fire from Trump, who has turned “socialism” into an attack line and charged that the Democratic presidential field has embraced an agenda being driven by the party’s liberal-wing.

The president has attempted to pin the label on Democratic opponents on Twitter and warned Americans about "new calls to adopt socialism in our country."

But Sanders is expected to push back against that criticism, charging that Trump just supports a different kind of socialism.

"While President Trump and his fellow oligarchs attack us for our support of democratic socialism, they don’t really oppose all forms of socialism," Sanders will say, according to excerpts of his speech released by the Vermont senator's presidential campaign. "They may hate democratic socialism because it benefits working people, but they absolutely love corporate socialism that enriches Trump and other billionaires."

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Sanders stands alone among the field of nearly two dozen major Democratic presidential candidates to identify as a “democratic socialist.”

The 2020 candidates, by and large, support policies to expand health care coverage, raise taxes on the rich, offer student-debt forgiveness and hike the minimum wage.

But some in the Democratic field part ways with Sanders on his calls for Medicare-for-All, a policy which would upend the private insurance system by expanding Medicare to cover every American, and his embrace of the Green New Deal, an ambitious proposal to curb climate change championed by fellow democratic socialist Rep. Alexandria Ocasio-Cortez.

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An intra-party debate

Sanders has faced pointed criticism in recent days from several Democrats trailing in the polls. They say an embrace of democratic socialism will lead to certain defeat in November 2020.

“We must be progressive, but also pragmatic,” Hickenlooper said in a speech before a gathering for Iowa Democrats Sunday. “We need a dreamer, but also a doer. We must present a bold vision for the future, but we also must acknowledge that the most effective charge Republicans can level against us is ‘socialism.’”

Both Hickenlooper and fellow 2020 candidate John Delaney faced jeers earlier this month at the California Democratic Party’s annual convention – a gathering of party activists and delegates – for their criticism of policy ideas that Sanders is embracing.

Delaney, as well as 2020 candidate Sen. Michael Bennet, have argued against Sanders’ Medicare-for-All pitch, saying it will lead to millions of Americans who prefer to keep private insurance coverage being pushed from their plans.

“Senator Sanders’ Medicare-for-All plan makes for a good talking point but is in fact bad policy and bad politics,” said Delaney, a former U.S. House member from Maryland.

Sanders in past public comments has described his views on democratic socialism as centered on creating a decent standard of living for all Americans. He made a speech in November 2015, months before the start of the 2016 primaries and caucuses, in which he explained his democratic socialist beliefs were not shaped by Marxism or an abolition of capitalism.

In his speech Wednesday, Sanders plans to nod to Franklin D. Roosevelt's 1944 State of the Union remark that "true individual freedom cannot exist without economic security and independence."

"Now, we must take the next step forward and guarantee every man, woman and child in our country basic economic rights – the right to quality health care, the right to as much education as one needs to succeed in our society, the right to a decent job, the right to affordable housing, the right to a secure retirement and the right to live in a clean environment," Sanders will say, according to the excerpts of the speech. "We must recognize that in the 21st century, in the wealthiest country in the history of the world, economic rights are human rights."

Sanders stands in second place in nearly all national and early-state polls behind former Vice President Joe Biden. In recent weeks, he has seen his support slip slightly, while backing for Sen. Elizabeth Warren, of Massachusetts, and South Bend, Indiana Mayor Pete Buttigieg has risen.

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He has offered some of the hardest jabs among Democratic hopefuls against Biden, dismissing the frontrunner for the Democratic nomination for offering “middle of the road” prescriptions on big issues like health care and income inequality.

But Biden, who has sought to bill himself as a centrist unifier, and other top tier candidates have yet to take on Sanders directly. Other Democratic candidates have attempted to delicately distance themselves from democratic socialist label, even while finding some common ground on policies with Sanders.

Warren, who like Sanders has sought to frame herself on the trail as a progressive champion of working people, said during a March interview with the writer Anand Giridharadas at the annual South by Southwest conference in Austin that she was not a democratic socialist. She told the writer that she believed there was “enormous amount to be gained from markets” but that “markets without rules are theft.”

"Markets have to have rules. They have to have a cop on the beat," she added.

Buttigieg on the campaign trail has charged that Trump and Republicans have tried to brand Democratic ideas as “socialist” to disparage ideas, but that the term has lost the negative connotation for younger Americans who did not grow up during the Cold War.

“A lot of people are throwing around these words like socialism, right?" Buttigieg said last month while campaigning in Iowa. "Mostly because they think it’s a kill switch on a Democratic idea like the Affordable Care Act, conceived by conservatives and invented by Republicans. And as soon as a Democratic president said we ought to do it, well, that’s socialism.”

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How do voters feel?

Americans today are more closely divided than they were earlier in the last century when asked whether some form of socialism would be a good or bad thing for the country.

While 51% of U.S. adults say socialism would be a bad thing for the country, 43% believe it would be a good thing, according to a Gallup poll published last month.

That marks a sharp contrast with a 1942 Roper/Fortune survey that found 40% describing socialism as a bad thing, 25% a good thing and 34% not having an opinion.

“Most voters care less about what you call yourself and more about what you’re going to do for them,” said Neil Sroka, a spokesman for liberal group Democracy for America. “That at its core is what most people on the left side of spectrum are focused on and what most voters are going to care about.”

Still, Jim Kessler, executive vice president at the center-left think tank Third Way, said that socialist tag, if it stuck, could be damaging.

Kessler noted the track record of candidates endorsed by the Sanders-aligned group, Our Revolution, during the 2018 midterm election. The group endorsed 35 candidates for gubernatorial, Senate and House races, but their candidates won just five of those races.

“We have never elected a national Democrat to the White House who is far to the left,” Kessler said. “Walter Mondale won one state. George McGovern won two. We are whistling past the graveyard if we think that’s changed.”