Democratic Sens. Cory Booker and Jeff Merkley have signed on to Sen. Bernie Sanders' single-payer healthcare bill expected to be released Wednesday.

The bill, which would expand Medicare to all Americans, has won signatures from prominent Democrats, a sign of the party moving to a fuller embrace of government-run healthcare.

"You should not be punished because you are working-class or poor and be denied healthcare. I think healthcare should be a right to all," Booker, of New Jersey, told NJTV News. "This is something that's got to happen. Obamacare was a first step in advancing this country, but I won't rest until every American has a basic security that comes with having access to affordable healthcare."

Merkley, of Oregon, said single payer can "simplify healthcare and lower patients' costs."

Booker is the latest 2020 Democratic hopeful to sign on to the bill. Sens. Elizabeth Warren of Massachusetts and Kamala Harris of California also are co-sponsoring the bill.

The bill is not expected to advance in the Republican-controlled Congress. However, it could be a central plank in the party's policy platform as more mainstream Democrats embrace the idea.