Sen. John Kerry's support for abortion rights and stem-cell research has prompted discussions among Roman Catholic bishops and Vatican officials over how to respond to a presidential candidate who professes Catholicism while taking stands contrary to church teaching.

The issue was a topic in the Vatican last week as bishops from Florida, Georgia and North and South Carolina held long-scheduled meetings with the pope and Vatican officials on a variety of issues.

"They are basically struggling with this, as we are," said one visiting American, Bishop John H. Ricard of Pensacola-Tallahassee, Fla., who chairs a task force expected to produce guidelines for American bishops on relations with Catholic politicians.

Most recently, he said, the bishops were troubled by Kerry's vote against a bill that makes it a crime to harm a fetus during an assault on a pregnant woman. President Bush signed the legislation, and the U.S. Conference of Catholic Bishops immediately issued a news release applauding him.

The task force that Ricard heads was formed last year after the Vatican released a forceful "doctrinal note" on "Catholics in Public Life," which said: "A well-formed Christian conscience does not permit one to vote for a political program or an individual law which contradicts the fundamental contents of faith and morals."

The bishops are unlikely to make overt endorsements, and consistently say that they favor neither Democrats nor Republicans. But if some influential prelates choose to publicly embrace or to snub Kerry - by refusing to offer him Communion, withholding an honorary degree or canceling an event at a Catholic venue - it could have an impact on some Catholic voters.

Catholics make up 27 percent of the electorate and belong to the largest church in the country, with about 65 million members. Many Catholics live in states with large blocs of electoral votes. Exit polls showed that Kerry did very well among Catholics in states that have already held their Democratic primaries.

Kerry is the first Roman Catholic to run for president on a major party ticket in 44 years, but the obstacles for Catholic politicians have turned inside out since 1960, when John F. Kennedy became the first Catholic to win the White House.

President Kennedy had to overcome accusations from non-Catholics that he would follow the bidding of the pope.

Now, Kerry faces accusations from some within his own church that he is not following the pope's bidding closely enough.