Sen. Bernie Sanders (I-Vt.) said Thursday that he would introduce legislation “in the very near future” that would make health care a right. (Molly Riley/AP)

Presidential hopeful Bernie Sanders highlighted his support for a single-payer health-care system — a position that separates him from his rivals for the Democratic nomination — during a Thursday rally on Capitol Hill celebrating the 50th anniversary of Medicare.

Sanders (I-Vt.) said he would introduce legislation “in the very near future” that would make health care a right, a goal he touts on the campaign trail and one that he has fought for unsuccessfully in Congress in the past.

“The time has come to say we need to expand Medicare to cover every man, woman and child as a single-payer national health-care program,” Sanders, a self-described democratic socialist, said at the rally, which was organized by National Nurses United and attended by members of an array of other labor unions.

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Medicare, which is available to those 65 or older, as well as younger people with disabilities, was signed into law by President Lyndon B. Johnson in 1965. Events across the country were staged Thursday to commemorate its launch.

Although Sanders’s position is not new, it helps explain his appeal to the progressive wing of the Democratic Party, and it is likely to factor into ongoing deliberations at the AFL-CIO over whom to endorse in the Democratic presidential primary.

As Medicare turns fifty, the politics of the plan are as hotly contested as ever. For Republicans, it's created a wedge among the presidential candidates. (Pamela Kirkland/The Washington Post)

Sanders appeared before the organization’s executive council on Wednesday in Silver Spring, and Democratic front-runner Hillary Rodham Clinton was scheduled to make her pitch Thursday. Labor leaders reportedly are torn between the two candidates and might wait to make a decision. Former Maryland governor Martin O'Malley also met with the AFL-CIO on Wednesday.

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At the Capitol Hill rally, Sanders was introduced by RoseAnn DeMoro, executive director of the 185,000-member National Nurses United and a national vice president of the AFL-CIO.

DeMoro referred to Sanders as a “rock star” and said he impressed labor leaders with his advocacy of a single-payer system during the closed-door appearance on Wednesday.

“I have to tell you, he is one of us,” DeMoro told the crowd.

Sanders was a supporter of President Obama’s Affordable Care Act but has said that it did not go far enough in providing universal coverage.

He said Thursday that supporters of a single-payer system should not be discouraged by pundits who say it has no chance of being embraced by Congress.

“All of the pundits always tell us what we cannot accomplish until the day after we accomplish it,” he said.