Associated Press
The U.S. Capitol building is seen Saturday, Nov. 19, 2011, in Washington.
In any congressional session, religious leaders will ... be embroiled in battles over food stamps, foreign aid, civil rights litigation, social security, funding for day care, environmental protection farm bills and the list goes on.

The American political landscape has seen a significant increase in religious advocacy groups since 1970, from 40 religious lobbies in Washington to over 200 today, according to a new study from the Pew Research Center. The groups are as dynamic as they are diverse, the study found, and represent everything from traditional American religious groups like Protestants and Catholics to smaller or newer religious movements in the U.S. such as Mormons and Muslims.

These groups have changed the political discourse on issues like gay marriage and abortion, as well as church-state questions like school prayer and aid to parochial schools. But according to leading researcher Allan Hertzke, religious advocacy doesn't end there."In any congressional session, religious leaders will ... be embroiled in battles over food stamps, foreign aid, civil rights litigation, social security, funding for day care, environmental protection farm bills and the list goes on," he said.

Catholic and Evangelical affiliated groups make up the majority of religious lobbies, while two religious minorities — Muslims and Jews — also have a significant lobbying presence compared to other faiths. The study's authors surmise that one reason these groups are so engaged in political advocacy is that as religious minorities, they are concerned with maintaining the ability to practice their religion.

Faith-based lobbying groups don't necessarily fall into one political party, or follow a certain ideological agenda, the study found. Groups like the Colorado Springs-based Focus on the Family, for example, advocate for "conservative" principles like the traditional definition of marriage, limited access to abortion, and school choice. Other religious lobby groups have policy objectives that are considerably more "liberal." For example People for the American Way and the United Church of Christ Justice and Witness Ministries advocate for civil rights, same sex marriage, and fair trade.

In Hertzke's book, "Representing God in Washington," a precursor to the Pew study, he warns that it is difficult to peg religious lobbies as wholly conservative or liberal. According to Hertzke, the Catholic Bishops have "in many ways have strategically placed themselves between ideological poles." They take what are widely considered "liberal" positions on certain issues while embracing many of the aims of fundamentalists on conservatives on social issues.

For example, in a recent pastoral letter to parishioners, the Conference of Catholic Bishops affirmed a traditional view of marriage stating, "'marriage' reflects a deep reality – the reality of the unique, fruitful, lifelong union that is only possible between a man and a woman." In the same time period they vocally opposed conservative efforts to impose enforcement-only immigration reform and encouraged increasing visa quotas.

The study notes that sharing a religious background does not mean groups necessarily agree on political issues. "Even groups with shared religious backgrounds come down opposite sides of policy debates," the study found. In some faith traditions, such as Judaism, or the Episcopal Church, a split has developed between traditionalist and progressive factions.

One example is the disagreement between various Jewish groups over US policy toward Israel. J Street, a left-leaning Jewish lobby organization, advocates for a two state solution to end the Israel Palestine conflict. On the other hand, the formidable American Israel Public Affairs Committee (AIPAC), which has been described as more conservative, vehemently opposes a two state solution.

In early 2011, J Street drew the ire of other Jewish lobbies, including AIPAC, when they suggested that Obama veto a UN resolution demanding Israel halt building projects in the West Bank. Pro-Israel lobbies responded with disbelief.

Another example of a schism within a religious group is illustrated by the controversy over gay marriage within the Black Protestant Churches. While many of the theologically conservative clergy oppose same sex marriage, others see it as a civil rights issue they support.

This divide is particularly pronounced within the family of the late Martin Luther King Jr. King's widow Coretta favors same sex marriage and has compared homophobia with racism and has said that if her husband were alive today he would affirm the civil rights of gays and lesbians to marry. On the other hand, King's daughter Bernice vehemently opposes same sex marriage. As an elder in an large Atlanta church she teaches that homosexuality is a sin and in 2004 organized a march in opposition to gay marriage that started at her father's grave.

According to Pew's calculations roughly 390 million dollars are spent annually by religious lobby groups in pursuit of their policy objectives. From 2008 to 2009 of the 40 biggest spenders, 14 were inter-religious groups, six were Jewish, six are Evangelical Protestants, five were Catholic, four were mainline Protestants and two were Muslim.

The report cites how religious groups successfully advocated for the 1998 International Religious Freedom Act, a campaign to advocate on behalf of persons in foreign countries persecuted because of their religious beliefs, and the Jubilee 2000 campaign, which focused on debt relief for poor countries at the turn of the millennium.

The study does not address the factors behind the rise of religious lobbying groups in Washington, but Christopher Morrisey, an adjunct professor at St. Mary's College, says it's a natural outgrowth in a country where religion matters to most of its citizens. "Explicit religious participation in public discussions makes sense and can be valuable," Morrisey says. "Many citizens think of policy issues in religious terms." He argues that while some people may don't like the influence of religious organizations in politics, "at least religious advocates make religion's contributions to clear and debatable rather than murky and unavailable."

Of religious advocacy groups Morrissey says, "I have learned that they are both idealistic and realistic about their roles in policy and governance. They want to influence the policy making process, but they know that actual influence is tough and often fleeting."

"Real influence" he said, "takes working in coalitions ... and long term focused effort."