The smartest, savviest people in Washington will tell you Bernie Sanders’ “Medicare for all” idea is dead on arrival, a waste of time and energy. But since those same smart, savvy people told you Donald Trump didn’t have a prayer of becoming president, I’d advise keeping an open mind.

What the Vermont senator’s bill has going for it is simple: It’s the right thing to do.

The issue is not whether we should have socialized medicine in this country. We already do—Medicare for everyone over 65; Medicaid for the indigent, the working poor and the disabled; the Children’s Health Insurance Program for minors in modest-income families. That’s a total of around 133 million Americans who already enjoy most of the benefits of a single-payer health system similar to those in other wealthy countries.

The philosophical debate about whether government should play a major role in medical care is over, as evidenced by the GOP’s “repeal and replace” fiasco. In trying vainly to get rid of the Affordable Care Act, Republicans argued about how to subsidize health insurance, not whether to do so. The most conservative approach—working through the existing free-market, fee-for-service health care system mediated by private insurance companies—had already been tried. It is called Obamacare.

In the end, Republicans couldn’t pull the trigger. The question now is whether Democrats will continue to settle for half-measures or finally demand what the party has claimed to want for decades: fully universal health care as a right, not as a privilege.

Sixteen Democratic senators have announced support for Sanders’ bill, introduced Wednesday, “to establish a Medicare-for-all national health insurance program.” It is no accident that among them are such potential 2020 presidential hopefuls as Kamala Harris of California, Elizabeth Warren of Massachusetts, Kirsten Gillibrand of New York, Cory Booker of New Jersey and Al Franken of Minnesota. They probably believe, as I do, that the party’s activist base is ready to go big on health care, even if the congressional leadership remains guarded and skeptical. Both Senate Minority Leader Chuck Schumer and House Minority Leader Nancy Pelosi are studiedly noncommittal.

There is, of course, the not-insignificant fact that Republicans control both the Senate and the House. Even though Trump has to be considered a wild card—he has, over time, taken every conceivable position on health care—it is hard to imagine this Congress jumping on the universal-care bandwagon.

But what Sanders did with his insurgent campaign for the Democratic presidential nomination was to bring “Medicare for all” in from the fringe and make it an acceptable topic for public debate. Medicare is enormously popular among seniors because it works. Why wouldn’t it work for the rest of us?

Critics reply that it would be ruinously expensive. They point to a 2016 Urban Institute study projecting that “Medicare for all” would cost a staggering $32 trillion over the next decade. However, this assumes the federal government would take over all current health care spending by state and local governments, employers and individuals, which would add up to $26 trillion over that same period. Even if this money were paid to the government rather than to health providers and insurance companies, according to this analysis, there would still be a sizable gap to somehow fill.

During last year’s presidential campaign, Sanders estimated that offering Medicare to all would cost $14 trillion over a decade and be offset by tax increases. He has not yet placed a price tag on the bill introduced this week.

There is another way to look at costs, however. According to the Organization for Economic Cooperation and Development, in 2015 the United States spent $9,507 per capita on health care. That’s more than twice the amount spent per capita in Britain ($4,125), France ($4,530) or Canada ($4,533), all of which have universal health care. In rankings based on factors such as life expectancy and infant mortality, the United States lags behind countries that spend much less on health.

As Trump and the Republicans in Congress discovered, health care is difficult. The details are devilish, but the big picture is clear: Our system is too byzantine, too expensive, too unfair. Other advanced nations produce better outcomes with single-payer systems that their populations would never trade for ours.

The ACA was a giant step on the road that leads logically to something very much like what Sanders is proposing. Progressives should take the next step by loudly and proudly proclaiming the destination.