The number of people without health insurance in the United States is estimated at 50 million. President Obama's health care law is aimed at making health care available to all of them. But it would also force the uninsured to get coverage.
The president and his expected Republican opponent Mitt Romney are on the eve of finding out if the U.S. Supreme Court will uphold all or part of the law.
The Supreme Court's decision on the Affordable Care Act will have some effect on the presidential campaign.
"If the decision goes against the president, if at least even a portion of the Affordable Care Act is thrown out by the Supreme Court, that creates a real difficulty for the president," said Dan Schnur, director of the Jesse Unruh Institute of Politics at USC.
And it's a potential issue for Romney to throw at the president. The most contentious part of the act is the requirement that most Americans carry health insurance. Opponents say that is unconstitutional.
Romney has made "Obamacare" a cornerstone of his attacks on the president and has said he would repeal it. He has been trying to use health care as a defining issue.
The president has defended the health care overhaul as critical to the public's health and well-being.
Schnur says whatever the high court decision is, by the time the dust settles the talk will be back to jobs and taxes.
"Both Romney and Obama are going to talk about health care a lot over the next several days because it rallies their respective bases: the most liberal of Democrats and the most conservative Republicans," said Scnur. "But swing voters don't care that much about this, they care about the economy."
Whatever the Supreme Court decides, the disagreement over how to provide health care to millions of Americans will be far from over. Neither will the battle over how to pay for it.
California currently has 7.2 million uninsured residents -- that's 19 percent of the state. If the law goes down, the state could lose $15 billion in annual federal funding.
"Through the Affordable Care Act, another 2 million approximately would be eligible for Medical coverage," said Lisa Rubino.
Rubino runs Molina Healthcare of California. She says even if the law is struck down, there will be some good news.
California has already passed coverage for children with pre-existing conditions, and young adults will be able to stay on their parents plans until age 26.
"If the law is not upheld, we still have to deal with, in California, 7 million uninsured," she said.
Most court observers seem to believe the court will at least throw out the mandate in a five to four decision. But you can't really ever predict what the justices will do. Justice Ruth Bader Ginsburg once said at the court, "Those who know don't talk. And those who talk don't know."