BOISE - Republican lawmakers in a handful of states are opening another front in the war against President Obama's health care overhaul, seizing on the hot-button issue of birth control with bills that would allow insurance companies to ignore new federal rules requiring them to cover contraception.

Measures introduced recently in Idaho, Missouri and Arizona would go beyond religious nonprofits and expand exemptions to secular insurers or businesses that object to covering contraception, abortion and sterilization.

"In its present state, the health care bill is an affront to my religious freedoms," said Idaho Republican Rep. Carlos Bilbao, who is sponsoring the bill.

The ACLU counters, saying such bills discriminate against women.

"Each time more entities are allowed to deny contraceptive coverage, the religious beliefs of some are imposed on others, and gender equality is undermined," said Monica Hopkins, the ACLU's Idaho director.

The bills echo a separate proposal in Congress sponsored by Missouri Republican Sen. Roy Blunt, allowing insurance plans to opt out of the requirement on contraception coverage if they have moral objections.

The measures are a direct challenge to a recent Obama administration decision that seeks to guarantee employees of religion-affiliated institutions reproductive health coverage, which includes contraception.

The controversy erupted nationally this year when the U.S. Conference of Catholic Bishops and other religious groups protested a new Patient Protection and Affordable Care Act rule that required church-affiliated universities, hospitals and nonprofits to include birth control without co-pays or premiums in their insurance plans.

Their opposition led Obama to modify the rule with changes that shift the burden from religious organizations to insurance companies, a solution that did little to satisfy the opposition and led to the statehouse challenges.

The bills, proposed by Republican lawmakers in conservative states, stand fair chances of passing.

As the issue shifts battlefields from Washington, D.C., to state capitols, it offers conservative lawmakers an opportunity to make it more difficult to obtain contraceptives they oppose on moral grounds.

Also, it provides another opportunity for opponents of "Obamacare" to renew the fight they see as a test of states' rights.

Idaho was the first state to pass a law requiring its attorney general to sue over the 2010 Patient Protection and Affordable Care Act. Arizona also joined the 27-state constitutional challenge that's pending in the U.S. Supreme Court.

In Missouri, some Republican officials have filed a lawsuit separately.

Americans "confront unprecedented government threats to their religious freedom, in particular from the federal government's newly enacted mandates relating to health insurance," said Gary McCaleb, a lawyer from the Alliance Defense Fund, an Arizona-based Christian nonprofit.

Planned Parenthood opposes the measures, arguing that they seek to meddle in essential women's health care that has helped reduce infant and maternal mortality.

"We're going to work to make sure women have access to this benefit no matter where they work," said Rachel Sussman, a Planned Parenthood senior policy analyst. "Only a few states are moving forward with this, and we think they're going to soon find out it's bad politics ... and it's bad health care."

Sussman said it's too early to say whether her group would file a legal challenge to these measures, should they pass, because they conflict with a federal law.

Ron Johnson, executive director of Catholic Charities Conference in Arizona, said at a hearing recently that passing the state law would give Arizona standing to sue the federal government over the regulation.

But constitutional scholar David Gray Adler, who directs the University of Idaho's McClure Center for Public Policy Research, says that should the measures pass, states will likely struggle to assert their laws over the federal rule.