(CNN) The future of health care in America has been the defining issue of the 2020 Democratic presidential primary. But liberal activist Ady Barkan, who is dying of ALS, believes the debate has been too shallow.

So, a few months ago, Barkan began asking the candidates to visit him in California for one-on-one conversations about their plans.

On Tuesday, Barkan's Be A Hero PAC, working with NowThis News and Crooked Media, released his discussion with Vermont Sen. Bernie Sanders , the author and leading proponent of "Medicare for All" legislation. Sanders on Friday night teased a forthcoming plan his campaign said would cancel $81 billion in existing past-due medical debt. The nearly 10-minute video moves between policy and the personal stories of the two men, with Barkan asking Sanders about fatherhood -- Barkan's son was born shortly before his diagnosis -- and an exchange about their legacies.

Barkan, 35, was diagnosed in 2016. He is now almost fully paralyzed and conducting the interviews with the aid of a computer that tracks his eye movements and then asks his questions in a synthetic voice.

"Senator, since my diagnosis, I have been thinking a lot about my legacy," Barkan said. "I'm curious, what do you want your legacy to be after you eventually exit the stage of national politics? How do you want to be remembered?"

"I hope that people will remember me as somebody who had the courage to take on virtually all of the powerful special interests in this country, in the fight for economic, social, racial, environmental justice," Sanders said in his interview, which was conducted during a recent stop in Los Angeles.

Sanders then turned to praise Barkan for his work, which first gained viral attention in 2017 during an exchange with former Republican Sen. Jeff Flake of Arizona and has grown in stature over the last couple years during Barkan's physically draining trips to Capitol Hill. In his most recent, and likely final visit, he testified at House "Medicare for All" hearings.

"In terms of your legacy, Ady, I think it will be very clear that even with the terrible illness that you're struggling with right now, that you didn't give up, that you understood that, especially given your illness, that you could play a significant in rallying the American people toward a sane and humane health care system," Sanders said. "And I think you will be remembered in very, very wonderful ways as a man of great courage in doing that."

The Sanders interview, along with Barkan's conversation with New Jersey Sen. Cory Booker , were posted online Tuesday. Barkan has also taped interviews with Massachusetts Sen. Elizabeth Warren, who highlighted his story during the last round of primary debates, California Sen. Kamala Harris and former Housing and Urban Development secretary Julián Castro.

Businessman Andrew Yang, Minnesota Sen. Amy Klobuchar and former Texas Rep. Beto O'Rourke are also confirmed for sitdowns with Barkan. Former Vice President Joe Biden's campaign has been invited, but not yet scheduled a meeting.

Barkan has not endorsed any of the primary contenders. Liz Jaff, the president of his Be A Hero PAC, told CNN on Tuesday that the goal of the series is not to pick a candidate, but to create more intimate conversations around the issue.

"He has realized, and this is the hardest part, that he can use his platform and his condition to make people watch and to call people to attention," Jaff said. "And to be honest with you, these candidates probably wouldn't be traveling to Santa Barbara to sit down for an hour in somebody's home if Ady wasn't who Ady was."

In a statement previewing the interviews, Barkan explained why he thought the format was necessary.

"Shouted thirty-second sound bytes and canned talking points just don't cut it when it comes to the crisis of tens of millions uninsured or out of control prescription drug prices," Barkan said. "People deserve better, and that's why I'm trying to host a different kind of conversation: one that pushes candidates beyond talking points, and to get personal and specific about one of the biggest crises in our society."

The taping process has been further complicated by Barkan's health. He had to postpone an interview last week with South Bend, Indiana, Mayor Pete Buttigieg after difficulty breathing made him sick, turning his feet blue. Barkan spent the next two nights in the hospital. Though he has health insurance, Barkan is still paying $9,000 out-of-pocket monthly for home care.

In his interview with Sanders, Barkan asked about the surge in "citizen advocacy" around health care expansion, and whether the senator was made to feel hopeful -- or angry, because such steps are increasingly necessary.

"Both," Sanders replied. "But I think the fact that people are standing up and fighting for justice right now will create the moment in the not-too-many years from now where people will not have to do that, where health care will be understood to be a right. What can we say other than it is cruel and insane that we have people who are on the GoFundMe websites in order to get funding for procedures that are life or death for them."