Perhaps Democratic candidate for president Sen. Kamala Harris wasn’t thinking when she cut loose with a sound bite she hoped would gain traction among voters. More likely, she was hoping listeners would not stop and think about what she said.

Harris, a Californian, is making “Medicare-for-all” a key plank in her platform. She and several other Democrat presidential hopefuls believe the idea will appeal to millions of Americans.

As they portray the idea, it just might be appealing. Harris and others promise “Medicare-for-all” would provide health insurance for everyone. You may remember former President Barack Obaa sold “Obamacare” the same way. That hasn’t worked out well for tens of millions of Americans.

Public opinion polls indicate Harris is on to something. Pollsters find that most people like the idea as liberals explain it: Free health coverage for all, with no one denied because of pre-existing conditions.

But then, pollsters provide the truth of the matter: “Medicare-for-all” would be mind-bogglingly expensive. Some analysts estimate the price tag could be nearly equal to the current total federal budget.

Liberals insist the price tag will be the problem of “the rich.” Stiff hikes in taxes — the kind that have sent capital fleeing from countries such as France where the strategy has been used — would be established, Harris and others explain.

It wouldn’t be nearly enough. Wiping out the assets of every billionaire in the United States might cover “Medicare-for-all” for one year. Then, Democrats would have to begin grabbing for the wallets of the middle class.

But the falsehood about how the scheme would be funded is only part of the lie.

Back to what Harris said several days ago: “Who of us has not had that situation, where you’ve got to wait for approval, and the doctor says, well, I don’t know if your insurance company is going to cover this? Let’s eliminate all of that. Let’s move on.”

Sounds great, doesn’t it?

But as millions of people who rely on Medicare know, the federal insurance program for older Americans often doesn’t cover certain health care treatments, either. “I don’t think your Medicare is going to cover this,” is a phrase too many have heard.

So millions turn to Medicare supplement insurance from the private sector, paying for it out of their own pockets.

Say goodbye to that safety valve if Harris and fellow liberals have their way. Under “Medicare-for-all,” no one would be allowed to carry private insurance.

She didn’t think to mention that, did she?