Just six weeks before midterm elections expected to punish Democrats, the president surrounded himself in a Virginia backyard with people who benefited from the law - a hemophiliac fearful of lifetime coverage limits that will now be eliminated, a senior citizen who got help with her heart medications.
Acknowledging that the economy is the foremost concern, Obama nonetheless insisted, "Health care was one of those issues that we could no longer ignore."
He highlighted some new reforms that take effect at the six-month mark Thursday, including new coverage for preventive care and young adults being able to stay on their parents' health care plans until age 26.
"I thank you from the bottom of my heart," one woman present, Norma Byrne of Vineland, N.J., told the president, explaining she was benefiting from the law's provisions that are closing the prescription drug coverage gap in Medicare.
Such gratitude isn't the norm. A new AP poll finds just 30 percent of people in favor of and 40 percent opposed to the 10-year, nearly $1 trillion bill to extend health coverage to 32 million uninsured. Another 30 percent were neither in favor nor opposed. The poll also found a high level of misunderstanding of what's actually in the bill.
Obama acknowledged he himself bears some responsibility for that.
"Sometimes I fault myself for not being able to make the case more clearly to the country," the president said.
Among benefits taking effect this week:
-Young adults can remain on their family's health plan until they turn 26.
-Free immunizations for kids.
-Free preventive care, like mammograms and cholesterol screenings.
-No more lifetime coverage limits, and annual limits start to phase out.
-Plans can't cancel coverage for people who get sick.
-No denial of coverage to kids with pre-existing health conditions.
Most of the big changes, such as the new purchasing pools and requirement for everyone to carry insurance, don't kick in until 2014, but Democrats hope that the more voters learn of the benefits, the more they'll like the bill.
With every House seat and a third of the Senate up for re-election six weeks from now, there are plenty of candidates who are being called to account for their vote in March on the health care legislation. And in almost every case the ones on the defensive are Democrats who supported the bill that the GOP branded as a budget-busting government takeover, not Republicans who opposed it.
In Ohio, GOP hopeful Jim Renacci takes aim at freshman Democrat Rep. John Boccieri, among the Democrats elected in Republican-friendly districts now targeted by the GOP. "Boccieri voted for Obama's health care bill, packed full of job-killing taxes," a Renacci ad says in an accusation echoed in GOP campaigns across the country.
Boccieri's ads don't mention his health care vote; none of the 219 House Democrats who support the legislation are talking about it in campaign ads. But several of the 34 Democrats who voted "no" can now boast of that vote, casting it as a sign of their fiscal responsibility or independence from Obama and party leaders.
In Virginia, an ad for Democratic Rep. Glenn Nye has him "voting against the health care bill, because it cost too much."
"The health care bill is playing a significant role in a number of campaigns across the country," said Rep. Pete Sessions, R-Texas, head of the National Republican Congressional Committee. "The legislation has alienated key demographic groups like seniors and independent voters."
Democrats and the White House play down the significance of the health bill as a campaign issue.
"Health care will play a role in individual campaigns, but this is not an election about health care," Dan Pfeiffer, White House communications director, said in an interview. "This is an election about jobs and the economy."
Associated Press writer Julie Pace contributed to this report from Falls Church, Va.