In an under-the-radar, late-September interview with "The Arena Talks" podcast, Democratic Sen. Brian Schatz (Hawaii) decried how single-payer has become a litmus test among progressives.

"I'll just make one broader point about healthcare and politics. It's only in healthcare where, if you are not for a single player, you are immediately a sell-out. It is only in healthcare where everything becomes a litmus test about your progressive purity," Schatz said.

"And I think that's nuts," he added.

Schatz made the point after discussing his own plan for healthcare reform, which is "Medicaid for All" or "Medicaid for anyone who wants to buy into it," as compared to the plan introduced by Sen. Bernie Sanders (I., Vt.), "Medicare for All."

"I think Medicaid should compete with these private sector options. I don't think it should necessarily replace the private insurance market," Schatz said.

The senator said his plan would increase competition in the private insurance market because Medicaid has a "pretty good" benefits package and is economically efficient.

"In every other space where we have a progressive priority – LGBT issues, women's issues – we are willing to, in the context of Republican rule, you know, take what we can get legislatively and pocket some wins," Schatz said.

When it comes to that lack of debate, Schatz cast some blame on the 2016 presidential election.

"In healthcare, I think partly because of the presidential campaign last year, it became so polarized that you weren't even allowed to have a good idea on healthcare unless you be some sort of creation from some neocon think tank," Schatz said.

Nevertheless, the senator wants Democrats to be at a place where they "can have a bunch of different progressive ideas" to debate in hearings.

"I'm open to a proper legislative process where we take three, four, five good progressive ideas – maybe even three, four, five moderate or conservative idea – and see what shakes out," Schatz said.

After Sanders introduced "Medicare for All" in September, a number of potential 2020 Democratic presidential candidates signed on in support, including Sens. Kirsten Gillibrand (N.Y.), Kamala Harris (Calif.) Elizabeth Warren (Mass.), and Cory Booker (N.J.). Shortly thereafter, however, the discord over healthcare amongst Democrates became clear. House Minority Leader Nancy Pelosi denounced the litmus test, and a number of other Democratic lawmakers had less than positive comments.

Schatz said he would be rolling out his plan in "the next couple weeks."