The “Medicare for All” bill that presidential hopeful Sen. Bernie Sanders released Wednesday is more likely to be litigated on the campaign trail than in the halls of Congress. And it highlights a rare political divide among Democrats on one of their marquee issues even as the party seeks to appear unified.

Supporters of the Vermont independent are vying with Democrats who prefer to expand and protect the 2010 health care law. Those differences have recently been overshadowed by larger fights between the two parties after the Trump administration broadened its position in a high-profile lawsuit by calling to strike down the entire 2010 law.

But the Sanders bill may become a point of contention in 2020 primaries. It is likely to be the most progressive and one of the most talked-about health care plans on the campaign trail.

Flanked by New York Sen. Kirsten Gillibrand, a 2020 rival, Sanders compared the movement for Medicare for All to the civil rights and women’s movements, vowing that it would end the health care industry’s for-profit motives that he says some people pay for with their lives.

“What we are involved in is not just health care legislation. We are involved in a great struggle,” he said. “This is a struggle for the heart and soul of who we are as American people.”