With a record of favoring eight of the last nine presidential election winners and a population that makes up about 20 percent of the electorate, Catholic voters could swing the national election in November, CNN reports.
However, the political impact of the visit of Pope Benedict XVI is uncertain.
"Benedict XVI is not a superdelegate riding into town to deliver a key endorsement," noted John Allen, CNN's senior Vatican analyst. "On the other hand, I think it would also be terribly naive to think there's no political subtext to the Pope's presence in the United States."
Once a solidly Democratic constituency, the Catholic vote now routinely switches between Republican and Democratic presidential candidates.
"The Catholic vote as a whole is a fascinating study because it is the quintessential swing vote in American elections," said Luis Lugo of Pew. "In 2000 they went, by about 3 percent, for Gore over Bush. In 2004 they went about 7 percent for Bush over Kerry, interestingly who was a Catholic candidate."
While Catholics are thought to favor Republicans because of that party’s pro-life platform, a Pew study claims that 51 percent of American Catholics think abortion should be legal in most or all cases.
Senator Hillary Clinton and Senator Barack Obama, the Democratic candidates for their party’s presidential nomination, are trying to avoid talking about their permissive abortion positions, highlighting other subjects where they believe they agree with the Pope.
In a CNN forum on faith last Sunday, Senator Hillary Clinton stressed her shared stand with Pope Benedict on social justice issues.
"He's been a strong voice on behalf of what we must do to deal with poverty," Clinton said, according to CNN. "And deal with injustice."
Clinton has won the Catholic vote in the Democratic primaries up to the present, though Obama is trying to win over Catholics in the key primary state of Pennsylvania with the help of the endorsement of Pennsylvania U.S. Senator Bob Casey, Jr., a pro-life Democrat like his governor father.
"Ironically, the first school I went to in Indonesia was a Catholic school," Obama said at CNN's faith forum. "So, you know, myself and Sen. Bob Casey -- who is sitting here -- we had pretty similar experiences probably."
The presumptive Republican nominee John McCain’s stand on the Iraq war could clash with the Vatican’s opposition to the conflict. However, the Pope has recently expressed concern that a hasty U.S. withdrawal from Iraq would precipitate a humanitarian crisis.
According to CNN, experts in both parties believe McCain could attract a majority of Catholics, but only if he expresses his own religious beliefs and stresses social issue stands, like his opposition to abortion.