Affordable health care for all is now at the center of the presidential debate. Two of the top three contenders for the Democratic presidential nomination -- Elizabeth Warren and Bernie Sanders -- support Medicare for All. The third -- Joe Biden -- and those hoping to take his place as the leading centrist in the race -- Pete Buttigieg and Amy Klobuchar -- have attacked the plan to contrast their candidacies from Sanders and Warren. Donald Trump, who wants to eliminate the Affordable Care Act itself, and has already added some 10 million people to the ranks of the uninsured, scorns it as "socialism," just as earlier Republicans libeled Social Security and Medicare itself when they were under consideration.

In 1984 and 1988, I made a single-payer Medicare for All plan central to my presidential campaign. As a policy, it has always made the most sense. The question has always been whether the politicians had the nerve to weather the fierce attack that insurance and pharmaceutical drug companies will unleash against the proposal and any candidate who supports it, and whether voters would be scared off by the attacks.

Sanders brought Medicare for All back into the national political debate in his remarkable run for the Democratic nomination in 2016 against Hillary Clinton. The National Nurses Association and others have helped build a movement out of that momentum. Sanders has "written the bill," and in the House, Rep. Pramila Jayapal has introduced a detailed complement to the Sanders bill. Elizabeth Warren, who signed onto the Sanders bill, now has produced a clear plan on what Medicare for All would cover, and how it would be paid for.

The basic principles and values are clear and widely popular. Health care should be a right, not a privilege. No one should go without the care they need because they cannot afford it. No one should go bankrupt simply because they get sick.

Yet our current health care system offends each of those principles. We spend almost two times per capita on health care as other advanced nations. If you have a lot of money or a strong union, you can get excellent health care. For the rest, care is rationed by money. Twenty-four million go without insurance, up 10 million under Trump. Another 65 million are underinsured, one serious illness away from bankruptcy. Health care costs are the leading cause of bankruptcy.

Medicare for All is popular at first look. Then the insurance and drug companies and the opponents unleash their arguments: government will mess it up, it will raise your taxes, it will take away your current insurance. Presented with that information, people's doubts grow.

So most of the opponents fly under a false flag: they lay on the arguments against Medicare for All, but claim they support health care as a human right and support some version of a public option, giving people the illusion of choice. The reality is that those plans will still leave millions without coverage and many millions more underinsured.

Warren came under particular attack in the debates and the media for not detailing how she would pay for her plan (Sanders has been clear on his plan). Now Warren has answered her critics. Her plan covers the cost of Medicare for All by raising taxes on the very wealthy -- largely a 3 percent surcharge on the wealth of billionaires -- and by requiring big companies to pay almost what they now pay for providing health care to their workers.

Her plan would save some $7 trillion of the $59 trillion it costs to provide health care to all over a decade, according to the Urban Institute by reducing overhead, eliminating insurance company profits, reducing monopoly and negotiating bulk discounts for drugs like every other advanced nation does. She would eliminate co-pays and premiums, returning $11 trillion to the pockets of working people, what she hails as the largest middle-class tax cut in history.

Once voters learn that under Medicare for All they can always keep their doctor, they won't be faced with co-pays or premiums, and they will be guaranteed comprehensive health care, support begins to build back up.

Now Sanders and Warren have doubled down on their argument. Warren now puts it to Biden and the other critics: "Every candidate who opposes my long-term goal of Medicare for All should put forward their own plan to cover everyone, without costing the country anything more in health care spending, and while putting $11 trillion back in the pockets of the American people," she writes. "If they are unwilling to do that, they should concede that they think it's more important to protect the eye-popping profits of private insurers and drug companies and the immense fortunes of the top 1 percent and giant corporations."

It's over three decades since I sounded the call for Medicare for All. Since then, health care costs have soared faster than wages, more companies have found ways to avoid covering more workers and more people have died or gone bankrupt because they couldn't pay for the care they needed. Now with Sanders and Warren, the debate is joined again. The naysayers say that Medicare for All isn't popular, that voters love their insurance companies. Sanders and Warren say voters love their doctors but are getting savaged by the drug and insurance companies. In the coming primaries, voters will have the opportunity to sort out what makes sense and what does not, and to show what is popular and what is not. This is a debate that is long overdue.

(You can write to the Rev. Jesse Jackson in care of this newspaper or by email at jjackson@rainbowpush.org. Follow him on Twitter @RevJJackson.)