(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.

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