Democratic presidential candidate Sen. Bernie Sanders, I-Vt., is pushing the lie that under his socialized health insurance program, people who lose their private insurance will keep their doctors and hospitals if they like them.

It's a variation of the lie that proved politically devastating to President Obama, who had repeatedly promised that people who liked their doctors and healthcare plans would be able to keep then under his plan, when in reality millions lost their preferred coverage as the program got implemented.

While Sanders concedes that people will lose their private coverage under his plan, he insists that it won't affect their choice of doctors or hospitals.

"What happens to the 180 million people in the private insurance market?" CBS's John Dickerson asked Sanders as he announced he was running for president in 2020.

“They will continue to go to the doctors they want, the hospitals they want," Sanders responded. "The color of their insurance card will change."

He also pushed the lie earlier in the interview, when Dickerson asked him about polls showing that support for "Medicare for all" proposals collapse once people realize it will mean they'll lose private insurance.

“That’s because we’re going to be taking on the insurance companies and the drug companies who are going to spend a whole lot of money distorting what we believe in," he said. "For example, they’re going to say to people, ‘You’re going to lose your current health insurance at employment.’ Yeah, but you’re going to have the same exact doctor. You’re going to have more freedom of choice under our proposal than you have under the current proposals. So there’s a lot of misinformation that’s going around on this issue.”

In reality, the misinformation is coming from Sanders. There's no way that Sanders can guarantee that every doctor and hospital on every insurance plan will participate in his government-run program.

Sanders likes to cite a study by the libertarian Mercatus Center as proving his point that his plan would save trillions of dollars. However, that number is based on an assumption that his plan would slash payment rates to doctors and hospitals by 40 percent relative to private insurance, which the study notes would bring payments, "to levels that are lower on average than providers’ current costs of providing care." The study warns, "It cannot be known how much providers will react to these losses by reducing the availability of existing health services, the quality of such services, or both."

Under the current system, doctors who accept Medicare and Medicaid are able to earn more money by shifting costs onto those paying privately. Eliminate private insurers, as Sanders would do, and it's a whole new ballgame.

The whole pitch for having a single federally-run financier of medical care is that it would allow government to use its bargaining power to drive down payments to providers. But the idea that all doctors and hospitals, many of whom have already lined up to fight socialized health insurance proposals, would simply absorb a major cut to their pay, and continue to participate in the government plan as if nothing changed, is detached from reality.