When political pundits talk about the power of religious groups to affect public policy in Washington, most tend to focus on the Religious Right.

Indeed, during the presidency of George W. Bush, Religious Right groups flexed a lot of political muscle and won numerous victories on Capitol Hill.

But the Religious Right has an Achilles' heel: Its leaders and activists are so closely identified with the Republican Party that when Democrats are in charge, these groups have a much more difficult time advancing their agenda.

That's not the case with the nation's other prominent religious lobby – the Roman Catholic hierarchy. Lobbyists representing the Catholic bishops are careful to work in both parties and as a result are often successful no matter which party is in charge.

Consider the recent flap over health-care reform. The bill passed by the House of Representatives on Saturday contains a stunning provision: It states that low-income women who receive tax credits to buy health insurance won't be permitted to enroll in any plan that covers abortion.

This language goes far beyond measures we've seen in other bills that bar direct tax funding to support abortion. The net effect of this language, many analysts believe, will be to force insurance providers to drop abortion coverage.

Any insurers who cover the procedure, after all, will be in effect ineligible from participating in the insurance exchange the bill creates. Most insurance firms are going to want to be part of that system, since it represents a lucrative new pool of customers. To get in it, they'll simply drop abortion coverage.

How did this restrictive language get in the bill? As National Public Radio pointed out, lobbyists for the Catholic bishops aggressively worked both sides of the political aisle in a bid to bring the bill into conformity with church doctrine. In addition, Catholic priests across the nation were ordered to sermonize about the issue during weekly services.

"The U.S. Conference of Catholic Bishops actively lobbied for the amendment, offered by Democrat Bart Stupak of Michigan and Republican Joe Pitts of Pennsylvania," reported NPR. "The Catholic Church, though opposed to abortion funding, has long advocated for universal health care as a fundamental human right and essential to the common good. Stupak was among 19 Democrats who in midsummer vowed to oppose any health overhaul plan that didn't specifically prevent taxpayer money from being used for abortions."

Americans United Executive Director Barry W. Lynn told NPR he is "horrified" by what happened.

"What we saw over the weekend was an act of unparalleled arrogance on the part of church officials," Lynn said. "Basically, they were claiming they would kill health care for the sick and the poor if the Democrats didn't give them the votes to impose religious doctrine into law. It's scandalous that this religious group has such extraordinary control over the fate of women's lives in this country."

I should point out that most American Catholics don't support the position taken by the church hierarchy and its army of lobbyists. A recent poll taken by Catholics for Choice shows that most Catholics support abortion coverage in health care reform, especially in cases of rape, incest and fetal abnormality.

Furthermore, 68 percent of Catholics say the church would be wrong to oppose the entire health-care reform plan merely because it includes coverage for abortion.

Efforts are under way to strip the language from the bill (which is on its way to the Senate), and religious leaders who oppose the bishops' move are speaking out. Yesterday, four prominent leaders signed a joint letter opposing the Stupak language.

Others are mounting a lobbying counter-offensive on Capitol Hill.

How will this shake out?

It's too early to tell, but there's at least a possibility that health-care reform – a goal many in this country have sought since the days of Theodore Roosevelt – will be scuttled thanks to the machinations of a powerful church that is determined to use the power of government to foist its dogma on all of us.

Remember this the next time you see some right-winger on the television or in a newspaper whining that religious groups are shut out of the public debate.