NEW ORLEANS - It was almost instantly called a momentous decision when a divided U.S. Supreme Court upheld the key portions of the Affordable Care Act, the massive overhaul of the nation's health care system.
The Supreme Court voted five to four to uphold the main points in the law.
The surprise was the swing vote by Chief Justice John Roberts, a conservative who decided to join four liberal justices in upholding the law.
The ruling affirmed a key provision that makes health insurance mandatory for most people. Citizens must pay a penalty to the Internal Revenue Service if they do not have insurance.
The majority ruling called it a legitimate use of authority to collect taxes.
Now the Affordable Care Act will touch virtually every American. The aim of the law is to provide coverage to more than 30 million people.
But, reactions have been sharply divided.
Mayor Mitch Landrieu called it a victory for tens of thousands of New Orleans residents.
Louisiana Gov. Bobby Jindal opposed it, and state Attorney General Buddy Caldwell called it deeply disappointing, saying congress does not have the authority to force Americans to buy health insurance.
President Barack Obama and Mitt Romney not surprisingly took opposing views.
"The highest court in the land has now spoken. We will continue to implement this law. We will work together to improve upon it where we can," Obama said.
"What the court did not do in its last day of session, I will do on my first day if elected president of the United States, and that is I will act to repeal Obamacare," Romney said.
Open enrollment for those who do not now have health insurance begins in October 2013, and the key portions of the law take effect in 2014, including the section that insurance companies will not be able to deny coverage to those with a history of medical problems, or charge them more.