The right to say no is a powerful force in America's history.

Government may not compel conscience. Pacifists can conscientiously object to military service. Students cannot be forced to pledge allegiance to the flag.

The power of no launched America. Some dissenters from the Church of England crossed an ocean to worship, raise children and form communities freely according to the dictates of conscience.

Four hundred years later, the right to say no to government is in peril. Religious groups by the dozens have been forced to go to court to ensure the federal government will let their no be no. They seek, simply, to protect the religious freedom that all Americans have enjoyed to this point.

On May 21, 43 Catholic groups joined 12 lawsuits against the Obama administration. They're protesting a mandate under the new health care law that forces employers to provide insurance coverage for contraception and sterilization — regardless of religious objections.

The lawsuits come after repeated appeals to the administration since last August by Catholic, Lutheran, evangelical and Jewish groups, among others, urging respect for religious liberty as it begins to implement the massive health care law.

But the religious exemption in the final mandate for women's preventive services issued by the Department of Health and Human Services — one of the first of many expected mandates under the new law — is far too narrow. So narrow that not even Mother Teresa would have qualified to exercise her conscience.

To opt out of the mandated coverage, a religious group must hire and serve primarily those of its own faith. That implies that the plaintiffs in these cases, and others like them, aren't religious enough to warrant an exemption.

We're talking about groups whose missions include serving inner-city children, the elderly, the deaf, HIV/AIDS patients, the developmentally disabled or terminally ill. (Picture a volunteer at a soup kitchen asking a homeless man with outstretched hands: "Excuse me, but are you Catholic?)

The University of Notre Dame and 42 other Catholic plaintiffs joined nearly a dozen groups that filed similar suits earlier this year. They include three evangelical educational institutions — Colorado Christian College, Geneva College and Louisiana College — that particularly object to HHS requiring coverage of abortion drugs.

These schools believe in, and teach, the protection of human life from conception. They should not be forced to sponsor health plans that offer the morning-after pill and Ella, a drug that can terminate a pregnancy days after fertilization.

As the presidents of the three colleges wrote in a piece published in April by the Wall Street Journal, groups that don't comply with the HHS mandate face steep fines:

"This 'conscience tax' is a blatant violation of the freedoms of religion and speech guaranteed by the U.S. Constitution and affirmed by federal laws such as the Religious Freedom Restoration Act. This mandate would be unjust even if it applied only to those who accept government funding, but it does much more than that. It applies to private, religious employers just because they exist in American society, regardless of whether they receive government funding."

The administration has talked a lot about providing an "accommodation" for religious groups. Sadly, that hasn't found its way into actual policy. The policy that has the force of law today is the same one that even some of the president's supporters — such as liberal columnist E.J. Dionne — found objectionable in January. Everything else has been only talk and hypothetical proposals.

Religious groups whose convictions will be trampled by the mandate on the books, having exhausted the potential of negotiation, took the next logical step by going to court.

Religious freedom has limits when it comes to serious issues concerning health, safety and welfare. No doubt hard cases will continue to emerge at the margins of the religious liberty debate.

This is not one of them.

The religious liberty principle at stake in the conflict over the HHS mandate is central to the First Amendment of the Constitution and to America's earliest purposes. It is the right — and responsibility — to say no to an overbearing government that disregards conscience.

Jennifer A. Marshall is director of the DeVos Center for Religion and Civil Society at The Heritage Foundation.