Voters will turn away from candidates pushing the idea in the end and claims the plan will improve access to quality health care are unfounded, Siegel said Thursday on "Fox & Friends."
"I think it's a campaign slogan. I don't think it's ever going to happen. They will self-destruct by getting behind it," he claimed.
"I can't believe they are making it a campaign issue. It's so unpopular."
The Fox News medical contributor said he believed many supporters of
Medicare-for-all plans have the popularity they do because they are pitched well by lawmakers who support them, the Fox News contributor said.
But, the NYU-Langone internist noted a quick poll of the special "Fox & Friends" studio audience showed no one raising their hands in support of it. He claimed that meant when the prospect of the government spending trillions of dollars on the measure is fully understood, it will sour public opinion.
Medicare-for-all "sounds great," he said. "What's it going to cost? $30 trillion over ten years. The hands will go down."
"Hands go down when you hear that in Canada - which is single-payer - you have to wait several weeks for an MRI, CT scan or a hip replacement, or to see a specialist. Who wants to wait several weeks to see a specialist?" he said.
In August 2017, Sen. Kamala Harris, D-Calif., became the first Senate Democrat to support Sen. Bernie Sanders', I-Vt., Medicare-for-all bill. During a speech to officially launch her 2020 run, Harris declared, "health care is a fundamental right," and vowed to support the legislation.
Sanders introduced an updated version of his plan on April 10.
Sens. Kirsten Gillibrand, D-N.Y., Cory Booker, D-N.J., and Elizabeth Warren, D-Mass., have also endorsed the plan or similar proposals. All are 2020 Democratic presidential hopefuls.
Fox News' Jennifer Earl contributed to this report.