WASHINGTON -- The last thing House progressives want is for the Supreme Court to strike down President Barack Obama's health care law. But if the high court rules Thursday that some or all of the law is unconstitutional, progressives are ready to renew their push for the model of health care they wanted all along: the single-payer option.

"It's easy to see it's a good idea," Rep. Keith Ellison (D-Minn.), co-chairman of the Congressional Progressive Caucus, told The Huffington Post. "It's the cheapest way to cover everybody."

Ellison said all 75 members of the caucus have already signed onto a bill by Rep. John Conyers (D-Mich.) to create a single-payer, publicly financed, privately delivered universal health care program. The proposal would essentially build on and expand Medicare, under which all Americans would be guaranteed access to health care regardless of an ability to pay or pre-existing health conditions.

House progressives pushed hard for a single-payer option, such as the "Medicare for all" approach, during the health care reform debate in 2009. But House Democratic leaders couldn't come up with the votes to pass the proposal, and progressives ultimately caved on the idea in order to pass the president's plan, on the reasoning that some reform was better than none at all.

Asked why progressives think a single-payer option could advance this time around, Ellison said if the Supreme Court strikes down some or all of the existing health care law, it shows that the individual mandate at the heart of the law -- a concept originally backed by conservatives -- was a failed approach.

"We've tried it the right-wing way. Let's try it the right way," he said.

Rep. Jerrold Nadler (D-N.Y.) said he led the charge for reviving the single-payer health plan during a recent Progressive Caucus meeting.

"We agreed we're going to come out in favor of Medicare for all, in both instances," he said, referring to the Supreme Court possibly striking either some or all of the health care law. "One disadvantage of saying, 'Let's go for single payer,' is that by and large the American people have no idea what that means. But the advantage of saying 'Medicare for all,' the American people do know what that means. And it's a very popular proposal."

Nadler said he didn't know how Democratic leadership would feel about revisiting the idea. He said that will depend largely on how the White House responds to the Supreme Court's ruling, whatever it is.

A House Democratic leadership aide suggested party leaders aren't about to embrace a single-payer option anytime soon.

"I think we have to recognize the situation we're in with House Republicans, where we can't even get bipartisan legislation finished," said the aide. "We can talk about specific proposals and have discussions and have that as something to focus on or talk to constituents about as they run for reelection. It's just not going anywhere in this Congress."

UPDATE: 1:45 p.m. -- White House Press Secretary Jay Carney later brushed off a question about whether Obama would support a single-payer option in the event his law gets struck down.

"The president favors the Affordable Care Act," Carney said at his daily briefing. "The president, as you are, is awaiting the decision. We will assess it as it comes."

UPDATE: 2:55 p.m. -- Progressives acknowledge there are obstacles but say it would still be best to embrace a "Medicare for all" approach.

"There's no chance that [House Speaker] John Boehner is going to bring that up for a vote," Rep. Peter Welch (D-Vt.) said on a conference call. "We have to have an alternative policy that we're promoting that shows where we want to go," he said, adding that he sees it as a long-term fight that could have short-term benefits in the fall.

"We'll have to start agitating and the two focuses for me will be what we're for -- Medicare for all -- and no. 2, indicting a Boehner-led House that has no Plan A, even to maintain the popular insurance reforms that mean a lot to the American people," he said. "It will be an opportunity for the American people to weigh in, in the election."

CORRECTION: A previous version of this article misidentified Keith Ellison as a representative from Missouri. He is from Minnesota.

Below, a slideshow of previous health care reform efforts:

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  • 1912

    Former President Theodore Roosevelt champions national health insurance as he unsuccessfully tries to ride his progressive Bull Moose Party back to the White House. (Photo by Topical Press Agency/Getty Images)

  • 1935

    President Franklin D. Roosevelt favors creating national health insurance amid the Great Depression but decides to push for Social Security first. (Photo by Keystone/Getty Images)

  • 1942

    Roosevelt establishes wage and price controls during World War II. Businesses can't attract workers with higher pay so they compete through added benefits, including health insurance, which grows into a workplace perk. (Photo by Hulton Archive/Getty Images)

  • 1945

    President Harry Truman calls on Congress to create a national insurance program for those who pay voluntary fees. The American Medical Association denounces the idea as "socialized medicine" and it goes nowhere. (Photo by Keystone/Getty Images)

  • 1960

    John F. Kennedy makes health care a major campaign issue but as president can't get a plan for the elderly through Congress. (Photo by Keystone/Getty Images)

  • 1965

    President Lyndon B. Johnson's legendary arm-twisting and a Congress dominated by his fellow Democrats lead to creation of two landmark government health programs: Medicare for the elderly and Medicaid for the poor. (AFP/AFP/Getty Images)

  • 1974

    President Richard Nixon wants to require employers to cover their workers and create federal subsidies to help everyone else buy private insurance. The Watergate scandal intervenes. (Photo by Keystone/Getty Images)

  • 1976

    President Jimmy Carter pushes a mandatory national health plan, but economic recession helps push it aside. (Photo by Central Press/Getty Images)

  • 1986

    President Ronald Reagan signs COBRA, a requirement that employers let former workers stay on the company health plan for 18 months after leaving a job, with workers bearing the cost. (MIKE SARGENT/AFP/Getty Images)

  • 1988

    Congress expands Medicare by adding a prescription drug benefit and catastrophic care coverage. It doesn't last long. Barraged by protests from older Americans upset about paying a tax to finance the additional coverage, Congress repeals the law the next year. (TIM SLOAN/AFP/Getty Images)

  • 1993

    President Bill Clinton puts first lady Hillary Rodham Clinton in charge of developing what becomes a 1,300-page plan for universal coverage. It requires businesses to cover their workers and mandates that everyone have health insurance. The plan meets Republican opposition, divides Democrats and comes under a firestorm of lobbying from businesses and the health care industry. It dies in the Senate. (PAUL J. RICHARDS/AFP/Getty Images)

  • 1997

    Clinton signs bipartisan legislation creating a state-federal program to provide coverage for millions of children in families of modest means whose incomes are too high to qualify for Medicaid. (JAMAL A. WILSON/AFP/Getty Images)

  • 2003

    President George W. Bush persuades Congress to add prescription drug coverage to Medicare in a major expansion of the program for older people. (STEPHEN JAFFE/AFP/Getty Images)

  • 2008

    Hillary Rodham Clinton promotes a sweeping health care plan in her bid for the Democratic presidential nomination. She loses to Obama, who has a less comprehensive plan. (PAUL RICHARDS/AFP/Getty Images)

  • 2009

    President Barack Obama and the Democratic-controlled Congress spend an intense year ironing out legislation to require most companies to cover their workers; mandate that everyone have coverage or pay a fine; require insurance companies to accept all comers, regardless of any pre-existing conditions; and assist people who can't afford insurance. (Alex Wong/Getty Images)

  • 2010

    With no Republican support, Congress passes the measure, designed to extend health care coverage to more than 30 million uninsured people. Republican opponents scorned the law as "Obamacare." (Mark Wilson/Getty Images)

  • 2012

    On a campaign tour in the Midwest, Obama himself embraces the term "Obamacare" and says the law shows "I do care." (BRENDAN SMIALOWSKI/AFP/Getty Images)

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