Supreme Court rules Obama's health care law constitutional

The Supreme Court upheld President Barack Obama's health care law Thursday, giving him an election-year triumph and a setback for Republicans.

In a 5-4 ruling based on the power of Congress to impose taxes, the court preserved the law's "individual mandate," which requires that most Americans obtain health insurance by 2014 or pay a tax, and reversed a provision of the law expanding Medicaid.

Obama called the ruling "a victory for people all over this country."

"We will continue to implement this law and we'll work together to improve on it," Obama said.

GOP presidential candidate Mitt Romney, however, called on voters to help him defeat the president in order to repeal the law.

Conservative Chief Justice John Roberts was joined by the court's four liberal members -- Justices Ruth Bader Ginsburg, Stephen Breyer, Sonia Sotomayor and Elena Kagan -- in upholding the "individual mandate."

The majority ruled that Congress' taxing authority allowed the mandate.

"Because the Constitution permits such a tax, it is not our role to forbid it, or to pass upon its wisdom or fairness," Roberts wrote.

In another part of the decision, the court said Congress went too far in a part of the law that requires states to expand the government's Medicaid health insurance program for the poor.

The court said this problem can be fixed by precluding the government from stripping states of existing Medicaid funds if they did not comply with the expansion, and that this did not require striking down other parts of the law.