By Eric Marrapodi, CNN Belief Blog Co-Editor

Washington (CNN) - When House Speaker John Boehner steps up to the podium at the Catholic University of America's commencement on Saturday, he'll be tap dancing around the line between faith and politics.

On Wednesday, a group of 70 professors, priests, nuns and others from the Washington university and other Catholic colleges around the country fired off a letter calling Boehner on the carpet for what they say is his lack of support of legislation for the poor.

"Your record in support of legislation to address the desperate needs of the poor is among the worst in Congress. This fundamental concern should have great urgency for Catholic policy makers. Yet, even now, you work in opposition to it," the letter reads.

Boehner, Catholic by faith and Republican by party, was able to garner enough votes in the House for the passage of HR 1, the House budget proposal that has drawn the ire of many religious leaders.

The group of professors said the proposed cuts in the budget to Medicare, the Women, Infants and Children (WIC) nutrition program and food stamps "guts long-established protections for the most vulnerable members of society."

Along with their letter they sent the speaker the Compendium of the Social Doctrine of the Church, a Vatican document on the teachings of the Catholic prepared in 2004 by the Pontifical Council for Justice and Peace.

The compendium cites specific guidance for lawmakers: "Those who exercise political authority must see to it that the energies of all citizens are directed towards the common good; and they are to do so not in an authoritarian style but by making use of moral power sustained in freedom."

Stephen F. Schneck is a professor at the Catholic University of America and director of the Institute for Policy Research and Catholic Studies. He is one of the signers of the letter and said the impetuous for it took root early in the budget debate.

"It was probably the contrast between what the bishops were telling us about paying attention to the needs of the poor and the actual budget that passed through the House of Representatives," Schneck said.

"One of the most ancient teachings of Christianity is preferential treatment of the poor, and it seemed that in the way in which the ... budget tried to address the deficit and the debt, it was particularly targeting programs that serve the poor," Schneck said.

"We thought that was an inappropriate balancing of the various interests of society. It seems to us these examples that we gave were illustrations of what were really egregious targeting of really valuable programs to the poorest and most vulnerable people in America."

Schneck and the other signatories on the letter are urging Boehner to join with a group of religious leaders who have been calling for a "Circle of Protection" to be formed around federal programs for the poor. That group grew out of what some have said are liberal Christian activist groups but in recent weeks has grown to include a broad scope of Protestant, Catholic and evangelical leaders.

“Lawmakers need to understand what a circle of protection means," Jim Wallis, the head of Sojourners, said on a conference call with reporters last week about the effort. "It means if you come after the poor, you will have to come and go through us first."

The coalition of religious leaders behind the "Circle of Protection" also has drawn the ire of conservative media outlets.

Rush Limbaugh said on his radio program last month, "A favorite tactic of the left, you know, when it suits them they'll talk about Jesus Christ. When they can convince or try to convince everybody Jesus Christ was the patron saint of liberalism, then they will herald Jesus Christ."

Boehner spokesman Michael Steel said the commencement address won't wade into the political battle over the budget. "The speaker will be delivering a personal, non-political message at the Catholic University of America that he hopes will speak to all members of the graduating class, regardless of their backgrounds or affiliations," he said in a statement to CNN.

"He is deeply honored to have been invited by CUA to address the school's graduating class and is looking forward to receiving an honorary degree from the only Catholic college in our country that is chartered by Catholic bishops,” the statement continued.

Steel also noted that an editorial in the student newspaper heralded the school's choice of commencement speaker.

Boehner is not the first Catholic politician to face criticism over how his politics and prayers mesh. During the 2004 presidential campaign, Sen. John Kerry, a Massachusetts Democrat, was denied communion over his support for abortion rights, which some bishops said was in direct violation of the church's teachings. Then-Rep. Patrick Kennedy, a Rhode Island Democrat, found himself in a similar row with his bishop in 2009 over abortion and was barred from receiving communion.

Schneck said any notion of whether Boehner's support for budget cuts would merit a withholding of communion is an "issue above my pay grade" and better left for a pastor, not a professor, to decide.

"I think the issue of a violation is one between him and God, but it seems the budget that has gone through the House of Representatives seems to be at odds with what should be the approach congruent with Catholic social teachings," Schneck said.

He also said the professors will not be disrupting the speech in any way and that their efforts were merely educational.

"Our efforts are to reach out to the speaker and hope to persuade him to think about endorsing the circle of protection."