The US Supreme Court Monday agreed to take up the case of President Barack Obama's landmark health care reform, which has come under fire from rival Republicans, in a move which could weigh on next year's elections.
The nation's nine top justices will "likely" hear the case in March, a court spokesman said, and are expected to rule on whether the reforms are constitutional by June, just months before the November presidential polls.
The court said they would consider a request by the Obama administration to declare the measure constitutional, as well as two cases challenging the law, including one brought by 26 US states and small businesses that want to strike down the totality of the reform.
Opponents say the most controversial feature of the law -- mandating that people buy health insurance or face a tax penalty -- violates individual rights as set out under the US Constitution.
A ruling against the legislation could be a major blow for Obama as he battles to win a second term.
But the White House said it was satisfied that the legislation, a key plank of Obama's 2008 White House campaign which passed into law amid much fanfare in 2010, was being taken up by the nation's top bench.
"We are pleased the court has agreed to hear this case," said a White House spokesman, Dan Pfeiffer, of the law which extended health coverage to an extra 32 million people and was the long-held dream of Democrats for social reform.
"We know the Affordable Care Act is constitutional and are confident the Supreme Court will agree."
The hearing on the case will last about five and a half hours, apparently "the longest in modern history," the court spokesman told AFP.
Republican opponents argue the government has no power to compel people to buy health insurance and Republican House Speaker John Boehner on Monday renewed his pledge to repeal the law.
"The American people did not support this law when it was rushed through Congress and they do not support it now that they've seen what's in it," he said in a statement.
Republican presidential hopeful Rick Perry also welcomed the court's decision to examine the legislation, calling it "an unprecedented overreach and an unconstitutional infringement upon individual liberties."
Analyst Ilya Shapiro said the case would be the most important examined by the court since the 1973 Roe v. Wade decision which legalized abortion in America.
"Both ways, it will not be good for the president. If it is struck down, his major accomplishment of his first term is gone," Shapiro told AFP.
"If it's upheld, it would energize not only the Tea Party and the Republican base but independents that overwhelmingly don't like this law."
Another expert said the decision could be almost as significant as the Supreme Court's ruling in 2000 which handed the presidency to George W. Bush over his Democratic rival Al Gore.
"But I don't think it could have a direct effect on the election result," Elizabeth Papez said, adding the vote of Justice Anthony Kennedy, who has been involved in many swing votes, could be key in the final decision.
Despite Obama's nominations to the Supreme Court of justices Sonia Sotomayor and Elena Kagan, the nine-strong bench, which acts as the nation's arbiter on the toughest legal and moral issues facing the country, has been viewed as one of the most conservative in decades.
Last year a controversial Supreme Court ruling lifted curbs on corporations, lobbyists, and special interest groups spending millions of dollars to back election candidates and influence outcome of US elections.
Lower court rulings have conflicted on the constitutionality of the health care law, and the top US court turned down two other requests to review the landmark legislation.
On November 8, a US appeals court upheld the constitutionality of health care overhaul, ruling that mandating that people buy health insurance or face a tax was not a violation of individual rights.
In August a federal appeals court in Georgia ruled that the individual mandate exceeded the powers of Congress, but also ruled that the remainder of the health care law was within the bounds of the constitution.