WASHINGTON - Amid a resurgent effort by critics to attack the 2010 health care law, the Obama administration and its allies are focusing on enrolling millions of Americans in coverage next year and making sure the new state health insurance exchanges will be ready for open enrollment in October.

But convincing a skeptical public to heed the Affordable Care Act's "individual mandate" will be a challenge when the bulk of the health care overhaul is fully implemented next year.

Polls show that not only do most Americans dislike the provision that requires them to get health coverage or pay a fine for noncompliance, but they're also confused about what coverage they should get, how to get it and how much it will cost.

To better inform people of their options, nearly 1,200 community health centers will use $150 million in federal grants to help spread the word. Florida Community Health Centers, for instance, which operates 10 facilities in central Florida, will use its $173,000 grant to hire three full-time benefit counselors and an outreach worker who'll seek out the uninsured for coverage.

"We go to beauty shops, barbershops, day cares, laundromats, churches and any other houses of worship. That's where people congregate," said Molly Ferguson, the centers' director of program development.

These and other federal grants will help with outreach efforts, but congressional Republicans' refusal to provide more money for a public awareness campaign has made the enrollment effort more difficult. The health care law was passed without GOP support.

Private administration-friendly organizations such as Enroll America, Young Invincibles and Organizing for America will be counted on to help the administration try to win the health law messaging war. But opponents of the law have been on the offensive.

A recent analysis by Kantar Media, which tracks political spending, found that critics of the Affordable Care Act have spent $400 million on television ads since the law passed, compared with just $75 million by its supporters.

A $1 million ad campaign against the law by Americans for Prosperity, a conservative political group funded by Kansas industrialists Charles and David Koch, is airing online and on cable in Ohio and Virginia.

"We feel it is important to educate Ohioans on the true consequences of government intrusion into the private health care decisions of families," said Eli Miller, the Ohio director of Americans for Prosperity.

The conservative Citizens' Council for Health Freedom has launched a national "Refuse to Enroll" campaign that urges people not to buy coverage through the exchanges.

The council, which describes itself as a "free-market resource" for health care issues, says the cost of coverage on the exchanges might be unaffordable for many, even with premium subsidies. The group claims that the exchanges will offer only limited choices of physicians and hospitals and that they require considerable paperwork to enroll. It likens them to "Medicaid for the middle class."

"We encourage Americans to get involved and make sure that the exchanges fail and, as a result, Obamacare also fails," said Twila Brase, the group's president and co-founder.

In response, the left-leaning Americans United for Change will launch a "Hands Off Obamacare" ad campaign on cable news stations beginning this week.

In the face of dwindling funds and negative ads, the Obama administration and public and private stakeholders will try to enroll about 7 million people for coverage on the exchanges from October to March.