(CNN) Vermont Sen. Bernie Sanders plans to introduce his new "Medicare for All" bill Wednesday morning, a move that will again push health care policy to the front burner of the Democratic presidential primary.

The new legislation's big-name co-sponsors include four of Sanders' fellow 2020 Democratic contenders -- Sens. Kamala Harris, Elizabeth Warren, Cory Booker and Kirsten Gillibrand -- all of whom also signed onto an earlier version Sanders put out in 2017.

By unveiling his proposal now, Sanders is effectively doubling down on his signature policy idea and betting that his calls to eliminate private medical insurers will be a winning one with Democratic voters, even as the party rallies around Obamacare amid an escalating court battle instigated by Republicans and backed by President Donald Trump.

But the move could light a match to a simmering debate within the Democratic Party, pitting Sanders against other candidates, including some of the Senate bill's co-sponsors, over the best path toward universal coverage. It is a fight Sanders appears to welcome. During the early stages of the 2020 campaign, he has relentlessly attacked private insurers, arguing that their presence is a malign influence on the whole of American health care -- a step, both rhetorically and on the policy front, that his opponents have so far refused to match.

Warren, Harris and Booker have all signaled their willingness to consider compromise plans that allow private insurers a role to play in any new or revamped system. They're up against moderates like Sen. Amy Klobuchar, who has said she is not in favor of Medicare for All, and Sen. Michael Bennet, who is planning to enter the race soon -- neither of whom are expected to join their more liberal colleagues.

The new legislation will update Sanders' 2017 bill, adding provisions to broaden its scope and potentially offer new details on Sanders' plans to pay for a program that could virtually wipe out the private insurance industry. More than 150 million Americans are currently covered by private insurance through their employers and tens of millions more through Medicare Advantage. Millions more buy coverage via the Affordable Care Act's exchanges.

Sanders, despite backing other less ambitious bills in the past, has ramped up his attacks on the industry, which he and many of his supporters view as greedy and the root of the problem Medicare for All is designed to fix.

"Today, we say to the private insurance companies -- we say that whether you like it or not, the United States will join every other major country on earth and guarantee health care to all people as a right," Sanders said at a rally in Los Angeles last month. "The goal of health care is to provide quality care to all, not to have insurance companies make billions of dollars a year off our sickness."

A recent calculation by Axios found that top health care executives brought in more than $1 billion combined last year -- a fact that Sanders, using similar numbers, has frequently cited on the stump as evidence of a "dysfunctional" system.

Under Medicare for All, everyone would be insured by a plan run by the federal government. It would cover all medically necessary care, including vision and dental. Private insurers could remain in business, but could only provide benefits -- such as elective surgery -- not covered by the federal plan.

The main sticking point: the cost, which would be largely borne by taxpayers. Estimates of the 2017 plan run as high as $32 trillion over 10 years. Sanders' team argues that many people would still come out ahead because they wouldn't have to pay premiums, deductibles or co-pays.

The Trump administration's decision in March to back a lawsuit that would strike down Obamacare triggered a unified round of backlash from Democrats, but it also highlighted the party's internal divisions, with moderates preferring to shore up the landmark health reform law and reverse many of the steps Trump and congressional Republicans have taken to undermine it.

But Sanders has long held that simply patching Obamacare or creating a buy-in to public programs would not solve the underlying problems.

"As long as you have private insurance companies as a part of that equation, you're going to have a system that is not purely interested in making people healthy and doing it in the most cost-effective way possible," a Sanders aide told CNN after the Trump administration announced its new position, suggesting that the renewed public focus on the issue could be a boon to Sanders' campaign.

"I don't know what it says about other candidates," the aide said, "but I think that it plays to his strengths as a candidate because he has a very clear message about health care and about the need to guarantee health care to every American as a right, not a privilege."

Support for Sanders' bill, which won 16 co-sponsors in 2017 after attracting none only a few years earlier, was framed by many on the left as a signal of the party's move left on healthcare and, in the context of a primary fight many have spent two years gaming out, his lead role in driving the debate. In speeches during the early phase of this second presidential campaign, Sanders has frequently reminded supporters that single-payer health care, an idea deemed "too radical" by the political establishment, has moved to the mainstream in the wake of his 2016 campaign.

Democratic candidates in 2020, like Warren, Booker and Harris -- among many others -- have almost uniformly endorsed a broad expansion of government-run health insurance. But they are less inclined to package it with a call to topple the private sector insurers.

Asked at a CNN town hall last month if there could be a role to play for those companies going forward, Warren didn't hesitate.

"There could," she told CNN's Jake Tapper. "Or there could be a temporary role. Even Bernie's plan has a runway before it gets there, because it's -- look, it's a big and complex system, and we've got to make sure that we land this in a way that doesn't do any harm. Everybody has got to stay covered. It's critical."

Booker, too, has been clear that private insurers would likely have a place even if Democrats can pass big-ticket health care expansion.

"Even countries that have vast access to publicly offered health care still have private health care," he said soon after announcing his candidacy.

Harris at a CNN town hall in January rattled off the complications that await many patients, including those with coverage, and said was ready to "eliminate all of that." But she has since offered a more nuanced position, in support of Medicare for All but with a continued openness to more incremental reforms and expansions.