PHILADELPHIA, Pennsylvania, May 15-- Facing a tight schedule as his motorcade squeezed through the narrow streets of Philadelphia on Monday, President Bush decided to risk arriving late at a White House function honoring the WNBA champion Houston Comets to grab a few moments with Cardinal Anthony Bevilacqua, the city's Roman Catholic archbishop.

The brief visit wasn't the first time that Bush, a devout and practicing Methodist, took time out from his schedule to huddle with a Catholic prelate. During the first four months of his administration, the president has met with Archbishop Justin Rigali of St. Louis, Bishop Donald Wuerl of Pittsburgh and had dinner with Cardinal Theodore McCarrick, then the newly installed archbishop of Washington.

The meetings provide only a hint of the emphasis Bush and his Republican allies are placing on recruiting Catholics, many of whom are antiabortion and socially conservative, into the GOP fold. Aides insist Catholics could emerge as the key to Bush's re-election effort in 2004. Karl Rove, the president's top political adviser, has said that of the nontraditional groups targeted by the GOP, the Catholics have been the most responsive.

An informal Catholic advisory group, consisting primarily of representatives from the church's conservative wing, gathers for a weekly conference call with White House officials. A group of prominent Catholics was brought in to discuss the president's faith-based social service initiative and the president himself has delivered an occasional speech honed specifically for Catholics.

"The pope reminds us that while freedom defines our nation, responsibility must define our lives," Bush said in March during a ceremony to commemorate the opening of the Pope John Paul II Cultural Center at Catholic University in Washington. "He challenges us to live up to our aspirations, to be a fair and a just society where all are welcomed, all are valued and all are protected."

For decades, the Democratic Party, the political home to New York Gov. Alfred E. Smith and President John F. Kennedy, monopolized Catholic voters. But Republicans are looking anew at the substantial voting bloc as a means of boosting party prospects.

Steve Wagner, a pollster who is part of the informal advisory group, wrote recently in the conservative Catholic magazine Crisis that religiously active voters have been migrating to the GOP since the 1970s because they found the Democratic Party to be "religiously indifferent."

Now, Wagner said, "it seems clear that religiously active Catholics are joining in, moving inexorably away from the solidly Democratic voting patterns that used to be a hallmark of American Catholics."

Bush looks to be picking up steam from the effort. He received 47 percent of the Catholic vote during the presidential campaign against then-Vice President Al Gore, who picked up 50 percent. That support is significantly better than Republican presidential candidates have traditionally received for instance, former Sen. Bob Dole, a Kansas Republican, lost to then-President Clinton by 16 percentage points in 1996.

During the last campaign, the Republican National Committee, through a group called the Catholic Task Force, compiled a list of about 3 million Catholics in 14 crucial states and peppered the households with phone calls and mail, citing Bush's views on issues important to those specific voters.

The effort didn't produce the desired results in Michigan or Pennsylvania, two states that went Democratic and almost foiled Bush's plans. But the GOP is continuing to recruit more than 4 million voters in swing states who attend Mass on a regular basis and view themselves as devout Catholics.