Michael Dukakis, former governor and Democratic nominee for president, is a fan of Elizabeth Warren, but not of the Medicare for All bill that would eliminate private insurance. In an interview with Boston Public Radio on Friday, Dukakis voiced concerns about the bill’s proposal to gradually phase out private insurance.

He hopes Warren will “walk back” her support of the bill.

“Every healthcare system in the world that I know, including the Brits where the government runs the system, lets you buy health insurance if you want to,” Dukakis said. “Just let people do what they want to do.”

The former governor added that he thinks it’s better policy and better politics to create a public option to compete with private health insurance. Among his concerns with eliminating private insurance are cost and fear that it will not win the support of union members.

“Why would you want to take it away from [unions]?” Dukakis said. “If we do the public option so people can buy into Medicare, that’s going to be 40 percent cheaper than private insurance.”

While the former candidate has endorsed Warren, he also said that he’s been impressed with Colorado Sen. Michael Bennet, who he considers “a good friend,” and former Vice President Joe Biden, who he said is a “good guy.”

Dukakis also said he doesn't think House Democrats should push for impeachment. While Dukakis is no fan of the president, he firmly believes a Republican controlled Senate will not convict the president and says Democrats should be focusing on issues that are of genuine concern to Americans.

“Why waste time on that when there are a ton of things we can investigate about this guy without that?” Dukakis said. “Our task beginning now is to organize a 50 state 200,000 precinct campaign ... connecting with the American people, and it’s time we got going on that. That’s what we need, not endless discussion about impeachment that’s doomed to failure.”

Clarification: This post has been updated to clarify that Dukakis is not supportive of a proposal to eliminate private insurance, but he is supportive of a public insurance option.