The U.S. Supreme Court announced Monday that it will judge the lawsuits against the health-care overhaul that is considered the outstanding legislative achievement of the government of President Barack Obama.

The high court is expected to hear the oral arguments beginning in March, which will place the controversy squarely in the middle of the electoral campaign.

The announcement represents a victory for opponents of the law, who say the requirement that all U.S. citizens buy medical insurance is unconstitutional.

Twenty-six states, all of them governed by Republicans, have challenged the legislation in federal court and several district judges have accepted their reasoning, but rulings at the appellate level have tended to favor the administration.

A three-judge panel of the U.S. Court of Appeals for the District of Columbia ruled last week that "ObamaCare" is constitutional.

Three other federal appeals courts have heard challenges to the Obama plan.

One upheld the measure, another found the insurance-purchase requirement unconstitutional and the third said challenges to the law are premature, as the measure does not take effect until 2014.

The Supreme Court has set aside 5 1/2 hours to hear the arguments in the case.

The White House, with what is considered its great political victory at stake in the hearing, on Monday hailed the Supreme Court decision to try the case.

"We know the Affordable Care Act is constitutional and are confident the Supreme Court will agree," White House communications direct Dan Pfeiffer said in a statement.

Though the law does not officially go into effect until 2014, and Americans are not obliged to buy insurance until then, the White House has already enacted some of its components.

Its approval would pave the way for the almost 50 million people without health insurance to obtain it.