Sen. Bernie Sanders (I-Vt.) introduced legislation Wednesday that would expand Medicare into a universal health insurance program with the backing of at least 15 Democratic senators — a record level of support for an idea that had been relegated to the fringes during the last Democratic presidency.

"This is where the country has got to go," Sanders said in an interview at his Senate office. "Right now, if we want to move away from a dysfunctional, wasteful, bureaucratic system into a rational health-care system that guarantees coverage to everyone in a cost-effective way, the only way to do it is Medicare for All."

Sanders's bill, the Medicare for All Act of 2017, has no chance of passage in a Republican-run Congress. But after months of behind-the-scenes meetings and a public pressure campaign, the bill is already backed by most of the senators seen as likely 2020 Democratic candidates — if not by most senators facing tough reelection battles in 2018.

The bill would revolutionize America's health-care system, replacing it with a public system that would be paid for by higher taxes. Everything from emergency surgery to prescription drugs, from mental health to eye care, would be covered, with no co-payments. Americans younger than 18 would immediately obtain "universal Medicare cards," while Americans not currently eligible for Medicare would be phased into the program over four years. Employer-provided health care would be replaced, with the employers paying higher taxes but no longer on the hook for insurance.

Private insurers would remain, with fewer customers, to pay for elective treatments such as cosmetic surgery — a system similar to that in Australia, which President Trump has praised for having a "much better" insurance regimen than the United States.

But the market-based changes of the Affordable Care Act would be replaced as Medicare becomes the country's universal insurer. Doctors would be reimbursed by the government; providers would sign a yearly participation agreement with Medicare to remain with the system.

"When you have co-payments — when you say that health care is not a right for everybody, whether you're poor or whether you're a billionaire — the evidence suggests that it becomes a disincentive for people to get the health care they need," Sanders said. "Depending on the level of the co-payment, it may cost more to figure out how you collect it than to not have the co-payment at all."

As he described his legislation, Sanders focused on its simplicity, suggesting that Americans would be happy to pay higher taxes if it meant the end of wrangling with health-care companies. The size of the tax increase, he said, would be determined in a separate bill.

"I think the American people are sick and tired of filling out forms," Sanders said. "Your income went up — you can't get this. Your income went down — you can't get that. You've got to argue with insurance companies about what you thought you were getting. Doctors are spending an enormous amount of time arguing with insurers."

Republicans, bruised and exhausted by a failed campaign to repeal the Affordable Care Act, were giddy about the chance to attack Democrats and Sanders. At Tuesday's leadership news conference, Sen. John Barrasso (R-Wyo.), a medical doctor, crowed that Sanders's bill had become "the litmus test for the liberal left" and that Americans would reject any costly plan for universal insurance coverage.

"Bernie Sanders's home state had … a similar plan," Barrasso said, referring to a failed 2014 campaign for universal health care in Vermont. "They realized they would have to double the taxes collected on the people of that state to pay for it because it was so financially expensive."

Sanders acknowledged that the plan would be costly but pointed to the experience of other industrialized countries that provided universal coverage through higher taxes. The average American paid $11,365 per year in taxes; the average Canadian paid $14,693. But the average American paid twice as much for health care as the average Canadian.

"Rather than give a detailed proposal about how we're going to raise $3 trillion a year, we'd rather give the American people options," Sanders said. "The truth is, embarrassingly, that on this enormously important issue, there has not been the kind of research and study that we need. You've got think tanks, in many cases funded by the drug companies and the insurance companies, telling us how terribly expensive it's going to be. We have economists looking at it who are coming up with different numbers. "

In 2016, when Sanders challenged Hillary Clinton for the Democratic presidential nomination, high cost estimates and the idea of wiping out private insurers kept many Democrats from embracing universal health care. While support for Sanders's proposal has risen from zero to 15, several Senate Democrats are proposing alternate plans for Medicare or Medicaid buy-ins, and Democratic leaders caution that their party will take no one-size-fits-all position.

"I don't think it's a litmus test," said House Minority Leader Nancy Pelosi (D-Calif.) of Medicare for All. "I think to support the idea that it captures is that we want to have as many people as possible, everybody, covered, and I think that's something that we all embrace."

Many supporters of Sanders have contradicted Pelosi, portraying his plan as popular — 57 percent of Americans support Medicare for All, according to Kaiser Health News — and efficient. Our Revolution, founded by Sanders, has urged Democrats to sign on; Justice Democrats, created after the election to challenge Democrats in primaries if they bucked progressive values, has asked supporters to call their senators until they endorse the bill. And a web ad paid for by Sanders's 2018 Senate campaign, asking readers to "co-sponsor" his bill, attracted more than half a million names.

As of Tuesday night, just one senator from a swing state had done so. Sen. Tammy Baldwin (D-Wis.), who as a member of the House had backed Rep. John Conyers Jr. (D-Mich.)'s Medicare for All bill, wrote a Tuesday op-ed for the Milwaukee Journal Sentinel to confirm that she was on board. The Republican Party of Wisconsin, which has struggled to find a first-tier challenger for Baldwin next year, was quick with a statement: "Senator Tammy Baldwin Embraces Radical $32 Trillion Health Care Takeover."

The $32 trillion figure was based on the Urban Institute's analysis of Sanders's 2016 campaign plan. The new bill was different — and so was the confidence Democrats had as they embraced it.

"With this reform, we would simplify a complicated system for families and reduce administrative costs for businesses," Baldwin wrote.

Kelsey Snell contributed to this report.

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