Obamacare's Insurance Rule Is Upheld by Supreme Court
The court's ruling on the law could figure prominently in the run-up to the Nov. 6 election in which Obama seeks a second four-year term against Republican challenger Mitt Romney, who opposed the law.
The ruling produced a day of drama at the Supreme Court, as the justices read various parts of the opinions from the bench on the last day of the court's term.
Roberts concluded his 59-page opinion by writing: "The Framers (of the U.S. Constitution) created a federal government of limited powers and assigned to this court the duty of enforcing those limits," he wrote.
"The court does so today. But the court does not express any opinion on the wisdom of the Affordable Care Act. Under the Constitution, that judgment is reserved to the people," he said.
The healthcare case produced four different opinions, totaling 187 pages.
U.S. House of Representatives Speaker John Boehner, the top Republican in Congress, renewed his vow to try to repeal the healthcare law.
"Today's ruling underscores the urgency of repealing this harmful law in its entirety," Boehner said in a statement just minutes after the court released its ruling.
Boehner's Republican-led House will likely vote to repeal the measure, but Obama's fellow Democrats in the Senate are certain to block it.
Obama and his fellow Democrats expended a great deal of energy and political capital in securing congressional passage of the measure over unified Republican opposition. The law is reviled by conservatives, who dubbed it "Obamacare."
The healthcare battle has been the most politically charged case before the Supreme Court since 2000, when the justices halted the Florida vote recount in a ruling that gave the Republican Bush the presidency over Democrat Al Gore.
Unlike healthcare in other rich countries, the U.S. system is a patchwork of private insurance and restrictive government programs that has left tens of millions of people uninsured.
The United States pays more on healthcare than any other country.