Some liberals say the biggest problem has been Democrats' failed effort to convince most Americans that the 2010 law is good for them. Provisions already in place, such as letting young adults stay on their parents' employer-provided health plans and barring insurance companies from denying coverage to minors with pre-existing conditions, have not triggered the public enthusiasm that Obama's allies predicted two years ago.
Heavy coverage of the Supreme Court case "gives us a chance to explain the law to Americans who are skeptical about it because they don't understand it," said Vincent DeMarco, president of the Maryland Citizens' Health Initiative and one of many activists standing outside the court building this week.
"They think it's a single-payer system, which it's not," DeMarco said. People also don't realize that requiring everyone to have insurance, including healthy people who seek few medical services, will lower costs for others and force insurers to stop discriminating against those with pre-existing conditions, he said.
If the Supreme Court strikes down the 2010 health law, some conservatives fear it will depress GOP turnout this fall because opponents no longer can argue that ousting Obama is the only way to kill "Obamacare."
Some conservative activists who demonstrated outside the court this week played down the potential impact on the presidential race regardless of how the court rules. Rejection of the law would chiefly raise questions about a Democratic-controlled Congress that passed such a flawed bill, said Jenny Beth Martin of Atlanta, co-founder of Tea Party Patriots.
Jim Manley, a former Democratic Senate aide, said Romney's likely nomination will negate the issue's impact in the presidential race.
"If the Supreme Court overturns this, the politics will take care of itself in November," Manley said. "But I guarantee Mitt Romney is not going to get any political gain out of this. He's tied at the hip" to the individual mandate being weighed by the high court.
EDITOR'S NOTE — Charles Babington covers politics for The Associated Press.
Associated Press writers Laurie Kellman and Henry C. Jackson contributed to this report.
An AP News Analysis
Copyright 2012 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.