While not a 2020 presidential candidate yet, Sen. Sherrod Brown (D-Ohio) broke from the pack of announced and expected Democrats on Friday by coming out against Medicare for All—characterizing a system that would cover everybody and leave nobody as not “practical”—and was greeted by a widespread reaction of “Thank you, Next” and “Adios” from progressives no longer willing to entertain half-measures when it comes to solving the nation’s healthcare crisis or bolstering the private insurance industry.

“I know most of the Democratic primary candidates are all talking about Medicare for all. I think instead we should do Medicare at 55,” Brown said during a question and answer session at the Chamber of Commerce in Clear Lake, Iowa. Brown said that reducing the age or letting people over 55 buy into the existing Medicare system early would have a better chance of getting through Congress.

“I’m not going to come and make a lot of promises like President Trump did … I’m going to talk about what’s practical and what we can make happen. And if that makes me different from the other candidates so be it,” Brown said.

Progressive critics like Splinter‘s Libby Watson, however, took issue.

“You know what isn’t practical?” she added. “Spending twice as much as other rich nations for worse outcomes.”

“It’s always ‘practical’ to leave people behind, and maintain corporate power,” tweeted Michael Lighty, a healthcare policy expert and founding fellow at the left-leaning Sanders Institute. But with the right kind of “leadership,” he noted: “We can make the necessary possible.”

Ahead of Brown’s comments, Watson on Friday wrote a long and detailed column explaining why the kind of “Medicare at 55” or “Medicare buy-in” plan the senator is proposing—basically a public option, but available only to certain segments of the population—is not just bad policy, but bad politics.

It’s not necessarily that what Brown is calling for would “make things worse,” she argued, “it’s that things are already catastrophically bad, and anything that just tinkers around the edges keeps us in dire straits.” And by not taking the fight over healthcare to the next level by demanding a policy that would actually solve the problem, Brown is exemplifying the worst tendencies of the Democratic Party’s old guard:

As The Hill notes, “Brown has increasingly been seen as a presidential candidate since his reelection victory in November, when he easily won another term in a state that voted for President Trump in the 2016 election.” The senator, the outlet added, “has been cast as a Democrat who could win states in the industrial heartland that the party lost to Trump in 2016, such as Michigan, Wisconsin and Pennsylvania.”