Ady Barkan, an activist with ALS who rose to national attention two years ago when he confronted then-Sen. Jeff Flake (R-Ariz.) on a plane, testified Tuesday in favor of Democrats’ Medicare-for-all bill, calling it “the only solution to what ails the American health-care system.”

Barkan, who was diagnosed with the degenerative disease three years ago, traveled to Washington from California, where he lives with his wife and young son. The disease has affected the 35-year-old activist’s tongue and diaphragm, making him unable to speak on his own. So he addressed the House Rules Committee with the aid of a computer that read his testimony out loud.

“Never before have I given a speech without my natural voice,” Barkan said. “Never before have I had to rely on a synthetic voice to lay out my arguments, convey my most passionately held beliefs, tell the details of my personal story.”

There is no known cure for Amyotrophic lateral sclerosis, or Lou Gehrig’s disease, a fast-moving neuromuscular disease that causes increasing paralysis and loss of vital functions. Each year, about 5,000 people in the United States are diagnosed with the disease, which has an average survival time of three years.

Barkan has advocated against the 2017 Republican tax overhaul and was among the 128 people arrested in a protest at the Capitol last year against the nomination of Supreme Court Justice Brett M. Kavanaugh.

He is an organizer with the Center for Popular Democracy and launched the “Be a Hero” campaign to mobilize voters in last year’s midterm elections.

In his 2017 encounter with Flake, Barkan told the senator that the disease struck him suddenly and that he will “probably need to go on a ventilator to live.”

“You know, I was healthy a year ago,” Barkan said at the time. “I was running on the beach. I’m 33. I have an 18-month-old son. And out of nowhere, I was diagnosed with ALS, which, you know, has a life expectancy of three to four years. No treatment, no cure.”

On Tuesday, the hearing room was silent as Barkan delivered his testimony via computer. He told the lawmakers that even though he and his wife have “comparatively good” health insurance, they still must pay $9,000 out-of-pocket every month for Barkan’s nearly 24-hour-a-day home care, relying on friends, family and a GoFundMe campaign.

“Like so many others, Rachael and I have had to fight with our insurer, which has issued outrageous denials instead of covering the benefits we’ve paid for,” he said. “We have so little time left together, and yet our system forces us to waste it dealing with bills and bureaucracy. That is why I am here today, urging you to build a more rational, fair, efficient and effective system.”

Tuesday’s hearing was the first-ever on Medicare-for-all, a proposal championed by progressives that would convert the U.S. health-care system into a single-payer model.

Sixty percent of respondents in a Pew Research Center survey last September said it is the government’s responsibility to ensure all Americans have health coverage — although the partisan differences are stark, with 49 percent of Democrats but only 12 percent of Republicans agreeing with the idea.

Barkan acknowledged that his time to deliver his message is running out. But he said he remains hopeful because there is a “mass movement” of Americans insisting that there is “a better way to care for one another, a better way to use our precious time together.”

“We have a once-in-a-generation opportunity to win what we really deserve,” Barkan said. “No more half measures. No more health care for some. We can win Medicare-for-all.”

Amy Goldstein contributed to this report.