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House Democrats will hold their first-ever hearing on Medicare for All legislation on Tuesday, advancing a sweeping proposal that several prominent 2020 Democratic presidential hopefuls have embraced -- even as some progressives caution the hearing may amount to a "farce," and President Trump and top Republicans call the idea a socialist prescription for disaster.

The 10 a.m. ET Rules Committee hearing concerns the Medicare for All Act of 2019, which promises to rapidly provide coverage for "all people living in the U.S." within two years, according to the current draft of the bill and a summary released by Washington Democrat Rep. Pramila Jayapal.

"I’m proud to announce this historic hearing on Medicare for All legislation," Rules Committee Chairman James P. McGovern, D-Mass., said in a statement. "We’ve made tremendous progress expanding health care over the years, most notably with passage of the Affordable Care Act. ... We have more work to do though and that’s why I’m a proud co-sponsor of this bill. It’s a serious proposal that deserves serious consideration on Capitol Hill as we work toward universal coverage."

The legislation has secured the backing of more than 100 congressional co-sponsors, including New York Rep. Alexandrai Ocasio-Cortez and Minnesota Rep. Ilhan Omar. Presidential candidates Pete Buttigieg, Cory Booker, Kamala Harris, Kirsten Gillibrand, Bernie Sanders, and Elizabeth Warren have endorsed some version of the proposal, while Amy Klobuchar has instead supported only a public option.

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Some progressives, however, are concerned Tuesday's hearing will amount to little more than "deliberation theater," charging that Wendell Primus, a top aide to House Speaker Nancy Pelosi, was involved in planning the hearing. In February, Primus reportedly told insurance executives not to worry about Democrats pushing the proposal.

Sen. Bernie Sanders, I-Vt., center, joined by Sen. Richard Blumenthal, D-Conn., center left, Sen. Kirsten Gillibrand, D-N.Y., center right, and supporters, speaks at a news conference on Capitol Hill in Washington, Wednesday, Sept. 13, 2017, to unveil their Medicare for All legislation to reform health care. (AP Photo/Andrew Harnik)

Sen. Bernie Sanders, I-Vt., joined by Democratic senators and supporters, unveils his Medicare for All legislation to reform health care. (AP Photo/Andrew Harnik)

But congressional Democrats have strongly pushed back on those claims, saying only the Rules Committee -- not the speaker's office or anyone else in the Democrat Party leadership -- has the final say over the proceedings, and that the hearing is designed to quickly but thoroughly consider Medicare for All.

Still, top Democrats have expressed skepticism on the legislation. Pelosi, for example, has said she is personally "agnostic" on Medicare for All, and openly wondered in a February interview with Rolling Stone magazine, "How do you pay for that?"

Republicans have invited Charles Blahous, a senior researcher at the Mercatus Center at George Mason University, as a witness on Tuesday to answer exactly that question. Blahous has authored a study finding that the plan would increase government health care spending by $32.6 trillion over 10 years, and lead to historic tax increases.

Those tax hikes, Blahous found, would offset the expense by only roughly $2 trillion. Blahous later charged that Ocasio-Cortez had wildly misinterpreted his study to try to argue that Medicare for All would save money.

Republicans have also invited Galen Institute president Grace-Marie Turner to testify. Turner warned in an op-ed last month of the potential consequences at stake: "Everyone would be required to give up the coverage they have now including 173 million American who get health insurance at work and taxes would be much higher to finance $32 trillion in added government spending over the next decade. For comparison, federal revenues last year totaled $3.4 trillion."

"How do you pay for that?"

— House Speaker Nancy Pelosi, on Medicare for All

In a statement, House Energy and Commerce Republican Leader Greg Walden characterized Medicare for All as an expensive, ineffective solution to a real problem.

“Health care is deeply personal – it impacts every single American," Walden said. "Patients and families want more choice and control over their doctors, treatments, and coverage. They want lower costs and greater access to care.  But government run, one-size-fits-all health care is not the answer. The Democrat plan is socialism. Under their plan, Americans will have fewer choices, taxes would skyrocket, and access to care would slow to a crawl.”

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Democrats, for their part, have invited several witnesses, including economist Dean Baker, physician Farzon Nahvi, Be a Hero founder Ady Barkan, who suffers from ALS.

But a report by the Huffington Post noted that "Medicare for All advocates may actually be getting screwed," because some of the Democrats' witnesses don't explicitly support Medicare for All.

One anonymous individual, who was proposed as a witness to the Rules Committee but rejected, wondered if the hearing wouldn't simply be a "farce" designed to defend the Affordable Care Act, rather than advance Medicare for All.

With the current Republican majority in the Senate, the proposal has no chance for passage at the moment. In an interview with Fox News earlier this month, Senate Majority Leader Mitch McConnnell, R-Ky., vowed to be the "grim reaper" of ideas like Medicare for All and the Green New Deal as long as he is in office. McConnell is up for reelection in 2020.

Tuesday's hearing comes on the heels of a report Monday by the government's overseers of Medicare and Social Security, which found that the financial condition of the government's bedrock retirement programs for middle-and working-class Americans remains shaky, with Medicare pointed toward insolvency by 2026.

In a statement, Jayapal, the representative introducing the legislation, said health care costs are unsustainable: “There is no other developed country on the face of the Earth that has a health care system that is as fragmented and costly as ours. The health outcomes and barriers to care in America are the worst of any industrialized nation. Health care is a human right and I’m proud the Rules Committee will be holding this hearing on the Medicare for All Act as this Majority discusses ways to strengthen our health care system for everyone."

Limiting her comments to Medicare, White House press secretary Sarah Sanders said Monday's report -- by three Cabinet heads and Social Security's acting commissioner --  highlights the need for "serious-minded" lawmakers to work with the administration on bipartisan changes to lower costs, eliminate fraud and abuse, and preserve the program for future generations.

AUSTIN, TEXAS - MARCH 09: Elizabeth Warren is interviewed live on stage during the 2019 SXSW Conference and Festival at the Moody Theater on March 09, 2019 in Austin, Texas. (Photo by Jim Bennett/WireImage)

AUSTIN, TEXAS - MARCH 09: Elizabeth Warren is interviewed live on stage during the 2019 SXSW Conference and Festival at the Moody Theater on March 09, 2019 in Austin, Texas. (Photo by Jim Bennett/WireImage) (Getty Images)

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Sanders also took the opportunity to criticize Democrats' calls to expand Medicare. She claimed such a step would amount to a "total government takeover of health care" that would cut out private-sector options, endanger access to health care for seniors and further strain the federal budget.

The issue is shaping up to be a pivotal one in the 2020 elections, with an Associated Press-NORC Center for Public Affairs Research poll finding that support for Medicare for All is concentrated mostly among Democrats -- not the independents that may hold the key to the White House.

However, the study found that Democrats enjoy a 17 percentage point advantage over Republicans in Americans' assessments of whom they trust more to handle health care, 40% to 23%. That compares with a public more evenly divided over which party would better handle several other major areas of national policy, including the economy, immigration and foreign affairs.

Fox News' Chad Pergram and The Associated Press contributed to this report.