Washington (CNN)Bernie Sanders isn't satisfied with the Supreme Court's affirmation last week of President Barack Obama's health care law.
Instead, the Democratic presidential hopeful said on Sunday he wants the United States to adopt a "Medicare-for-all" single-payer health care plan.
"We need to join the rest of the industrialized world," Sanders said on ABC's "This Week."
Sen. Sanders:"very positive reaction" to SCOTUS ruling 01:42
His comments illustrate Sanders' appeal to Democrats' liberal base, where his criticism that Obama's health care law didn't go far enough is just one of many areas he's pushing the debate farther left. They also underscore the challenge facing the party's frontrunner, Hillary Clinton, who is trying to navigate through a primary against Sanders without sacrificing her ability to appeal to a broader swath of the electorate.
Meanwhile, Sanders' commitment to liberals causes has caused him to gain on Clinton in recent polls. According to a new CNN/WMUR New Hampshire Primary poll, Clinton holds just an 8-point edge over Sanders, with 43% behind Clinton and 35% backing Sanders.
Photos: Supreme Court: Force for change?
The Supreme Court ruled 5-4 that same-sex marriage is legal nationwide, a decision that profoundly affects the lives of millions of Americans. Some legal scholars see the court's movement on gay rights issues as proof that it is a force for change. But others say the court's role is largely the opposite.
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Photos: Supreme Court: Force for change?
Another major ruling upheld Obamacare subsidies; had it gone the other way, millions could have lost their health care tax credits. Some legal scholars say the court's historical mission has been to block change, not validate it, by defending the status quo and ruling in favor of "wealth, power and privilege."
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Photos: Supreme Court: Force for change?
They point to a 1918 ruling that struck down a federal law banning child labor, which left the practice in place for another two decades. The court said the law was "repugnant to the Constitution" because it violated states' rights. At the time, millions of children worked in dangerous mines, dank sweatshops and textile mills such as this one in Vermont in 1910.
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The court has been on the wrong side of history numerous times, says author Ian Millhiser of the Center for American Progress. It issued decisions that legitimized Jim Crow segregation, approved the forced sterilization of a woman against her will and forced Japanese-American citizens into internment camps during World War II.
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Other scholars such as Clark Neily of the libertarian public interest law firm Institute for Justice defend the court, saying Brown v. Board of Education -- which led to school desegregation, including in Little Rock, Arkansas, in 1957 -- shows that the court is often "better than the other branches of government and society in general."
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Photos: Supreme Court: Force for change?
Critics say the court makeup is part of the problem, noting that most justices have been white men from privileged backgrounds. It's an issue, they argue, that can sometimes lead to paternalistic language, as in a 2006 abortion ruling that said "some women come to regret their choice to abort the infant life they once created and sustained."
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Many court critics have also questioned the wisdom of the 2010 Citizens United v. FEC decision, which opened the floodgates for campaign financing, allowing outside groups to spend record amounts. Millhiser said the ruling "gave billionaires a far-reaching right to corrupt American democracy."
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Sanders complained that the country is "spending almost twice as much per capita on health care as do the people of any other country."
"We are the only major country on earth that doesn't guarantee health care to all people as a right and yet we end up spending much more than they do," Sanders said.
"So I do believe that we have to move toward a Medicare for all, single-payer system," he said. "I think it's not going to happen tomorrow, but that certainly should be the goal."
Conservative backlash against Obamacare, which critics said amounted in a government takeover of health care, led to Republicans winning back the House and Senate in recent elections. Sanders' plan would in fact be such a takeover.
