This is a pivotal moment in American history. Do we, as a nation, join the rest of the industrialized world and guarantee comprehensive health care to every person as a human right? Or do we maintain a system that is enormously expensive, wasteful and bureaucratic, and is designed to maximize profits for big insurance companies, the pharmaceutical industry, Wall Street and medical equipment suppliers?

Senate Democrats are set to announce a new push for single-payer healthcare on Wednesday featuring several 2020 hopefuls touting legislation from Sen. Bernie Sanders, I-Vt., to expand Medicare to everyone.

But divisions remain in the Democratic caucus over whether government-run healthcare may be going too far. Some of the most vulnerable Senate Democrats running for re-election in 2018 are not offering a warm embrace of the policy.

When Sen. Bernie Sanders last introduced a single-payer bill in 2013, it didn’t attract a single co-sponsor. Now, as he unveils his “Medicare for all” bill on Wednesday, some of the biggest names in the Democratic Party will be by his side.

The Connecticut Democrat will advance a plan he argues “may be the fastest way to a single-payer system.”

Sen. Bernie Sanders’ (I-Vt.) Medicare for all plan has become a key test for Democrats with 2020 presidential ambitions.

Sen. Kamala Harris (D-Calif.) announced during a town hall on Wednesday that she would support Sen. Bernie Sanders's (I-Vt.) "Medicare for All" bill, which would institute a single-payer health insurance system.

Elected officials in both parties, but especially Democrats, are failing the American people on health care. This failure to think outside of the box is what’s kept our country from joining the rest of the industrialized world in offering universal health care. We live in a country that sent people to the moon.

America's doctors are warming to the idea of single-payer healthcare. A new survey from consulting firm Merritt Hawkins finds that 56 percent of doctors support a government-run system at least somewhat, with 42 percent expressing strong support.

Two years ago, if you had asked me about the prospects for a single payer health care system to be adopted in the United States, I would have said that there was essentially no chance in the foreseeable future. Single payer would be too expensive and too disruptive to both patients and providers. Even if you could cobble together a semi-functional legislative plan, the politics would never work. Short of catastrophe, there was no way it would ever happen.

Earlier this week, Aetna, one of America's biggest insurance companies, pulled out of Obamacare's insurance exchanges. Now its CEO thinks it's time for America to start talking about moving to a single payer health care system.