For now, however, it's shaping up to be more of a talking point for the party than a reality.
Sen. Joe Manchin of West Virginia, widely considered the most conservative Senate Democrat, said Tuesday that single-payer "should be explored," even while saying he was "skeptical" it would be the right choice in the end.
Add on prominent business leaders and growing public interest, and single-payer is moving from the fringe of the US healthcare debate to the spotlight.
But there's a simple reason such a plan won't be enacted into law anytime soon: Democrats don't have close to enough votes, as they don't control either chamber of Congress, and there is a Republican president in the White House. Given a deficit in the House of Representatives and an unfavorable 2018 Senate map for Democrats, there's at least four years or an electoral bloodbath before any turnaround in congressional control.
Republicans were able to use the budget reconciliation process - which means a bill can pass the Senate with only 50 votes - for their attempt to repeal and replace Obamacare earlier this year only because their plans would've decreased the federal deficit. A bill that would possibly add millions to a program paid for by the federal government would be unlikely to do the same.
Another sticking point for Democrats is that neither House Minority Leader Nancy Pelosi nor Senate Minority Leader Chuck Schumer have come out in support of the idea. Pelosi on Tuesday said her focus was on stabilizing and improving the Affordable Care Act.
Despite legislative roadblocks, it does seem like the public is coming around to the idea of a single-payer system - but they're less inclined to be supportive of specific elements. According to a poll by the Kaiser Family Foundation, a nonpartisan health policy think tank, 53% of Americans said they would support a single-payer type of insurance program. When sold as "Medicare-for-all," as Sanders' bill is, it ticks up to 57% in favor.
"The poll finds the public's attitudes on single-payer are quite malleable, and some people could be convinced to change their position after hearing typical pro and con arguments that might come up in a national debate," Kaiser wrote.