Sen. Bernie Sanders (I., Vt.) said that if his Medicare-for-All tax plan is adopted, he will impose tax hikes on the middle class because "health care is not free." Sanders's comment came in response to a question from the Washington Post‘s Robert Costa during an interview on Tuesday.

"Should the middle class at all have a stake in creating a system like Medicare-for-All through a bit of a higher tax rate?" Costa asked.

"Well, of course," Sanders replied. "How do you think we … Health care is not free. Now, we pay for health care in a variety of ways, pretty complicated. About half of health care dollars, more or less, comes from taxes."

At the same event, Sanders said that his Medicare-for-All plan would probably cost $40 trillion over a period of 10 years.

"Somewhere between $30 and $40 trillion over a 10 year period," Sanders said, claiming that his plan would be cheaper than that of former vice president Joe Biden. "What the most serious economists tell us, that if we do nothing to fundamentally change the healthcare system, which is what Joe was talking about, keeping it as it is, we'll be spending something like $50 trillion over a 10 year period."

Sanders's chief rival in pushing Medicare-for-All, Sen. Kamala Harris (D., Calif.), said during a Tuesday interview with CNN that she did not support raising taxes on the middle class in her version of the plan. Harris, however, was unclear on how she would achieve this goal.

"I mean, I'm not in support of middle class families paying more taxes for it." Harris said. "Part of it is going to be about Wall Street paying more. It's going to be about what we tax in terms of financial services. That's part of it. The other part is to ups understand this is about an investment that will reap a great return on the investment. We can't only look at this issue in terms of cost without thinking about benefit. The benefit to the American public will be that people will have access to health care that right now they cannot afford. And we are all paying a price for that."

Harris has been unclear about other positions on health care, supporting removing private insurance entirely in the beginning of the year, a position she later retracted.