Cardinal Timothy Dolan's appearance Thursday night at the Republican National Convention, according to the New York Archdiocese, is purely pastoral. No politics involved, even though the cardinal has been embroiled in a political fight with the Obama administration for months now over religious liberty -- specifically, the health care law's contraception mandate.

From kickoff to sendoff, religious voices from various traditions have taken center stage this week at the Republican get-together in Tampa, Fla. Prayers have been offered by a rabbi, an evangelical pastor, the president of a Sikh temple and a Greek Orthodox archbishop.

But no member of the clergy has garnered as much attention as Cardinal Dolan. He will give the benediction, a blessing tonight, drawing the convention to its close. It's a departure from standard procedures -- normally the local bishop would be asked. But Dolan, who's also the president of the U.S. Conference of Catholic Bishops, is the nation's highest-ranking Catholic and has been the voice of religious liberty, a leading issue for the GOP, in the fight over ObamaCare.

The invitation to offer the closing prayer came last week. And criticism was quick to follow, claiming Dolan was a shill for the Republican Party.

But earlier this week, the Democratic National Convention extended the olive branch.

And Dolan will give the benediction there next week in Charlotte, N.C.

Bill Donohue, president of the Catholic League, said that essentially the Democrats' backs were against the wall.

"After all, if you have the head of the USCCB speaking and closing the Republican National Convention, and you're bringing in somebody else at the Democratic National Convention who's Catholic, it almost looks like you didn't get the first choice. You didn't get the big guy."     

But one left-leaning Catholic who blasted the cardinal's RNC appearance now says Dolan should stay out of the political ring altogether.

Michael O'Loughlin, a blogger for America Magazine, says, "I think some people might see your (the cardinal's) presence there as less than genuine. Are you looking to amass political power for the Church? Are you looking to give a subtle endorsement? Even if you are unable to give an official endorsement. What is your purpose there?"  

Dolan said yesterday on Sirius Radio that "Part of prayer is conversion of hearts. When you pray you are asking the Holy Spirit to purify us and bring out what is most noble. Part of my prayer, for both parties, would be that they would be true to the biblical, to the theistic, to the natural law traditions of this country.  And that can be prophetic, and that can be a call to conversion when they’re not.”

It is the Catholic Church, with Dolan as its banner spokesman, that's led the battle against the health care law's mandate which the church says forces religious institutions to violate church teachings requiring them to offer benefits like contraception and abortion-producing drugs.  

Pundits expect a warm reception for Dolan tonight. It'll be a little like preaching to the choir.

But next week in Charlotte, for the DNC event, may not be so warm and cozy.  The Catholic Church takes a doctrinal hard-line against abortion, same-sex marriage, and, of course, the mandate . . . all of which are part of the Democrats' platform.

Donohue says, "He won't be particularly warmly received. It'll be very polite. And I think he knows what he's getting into."

But Dolan will not be the only Catholic voice to speak next week. Sister Simone Campbell, a radical nun who's the executive director of The Network will also address the assembly. She is the leader of the "Nuns on the Bus" tour for social justice. Campbell and her group have been butting heads with the Vatican over some of its practices and lax stance on church teachings.

O'Loughlin says, "I think that voices like Sister Campbell's are necessary. It's good to have leaders of the Church offering viewpoints on . . .a wide variety of issues. And she and her group have been very active in speaking out for the poor."

But Dolan himself has said the Catholic Church is not siding with the Republican or Democratic party. In fact, he released a statement Monday to both Republican nominees Mitt Romney and Paul Ryan, and President Obama and Vice President Joe Biden, asking them to sign the Civility in America Pledge developed by the Knights of Columbus. The pledge calls on candidates, commentators and members of the media to focus on critical issues and "avoid personal attacks."

Where once Catholics were solidly in the Democrats’ camp, over the past four decades they’ve become a crucial swing vote, a barometer for the general election.

Donohue says in the 2008 contest, among regular Mass attendees, John McCain bested Barack Obama by 1 percent.

With a few weeks to go in the campaign, both parties will be working to woo this critical group. The conventions are the first real test.