This could be troubling news for the McCain campaign, since the voters in question are a sizable — and sometimes decisive — bloc.

From the WSJ:

For the first time since the presidential election of 1988, the observant white Catholic vote might be up for grabs this November.

Conservative Catholics now appear to be more concerned about the economy and the war in Iraq, and less motivated by abortion, the issue that has long kept the voting bloc aligned with Republicans.

The shift may be bad news for Sen. John McCain, but it also poses a challenge for Sen. Barack Obama in some critical swing states where a majority of Catholic voters supported Sen. Hillary Clinton in the Democratic primaries.

Since the 1970s, the country’s roughly 64 million Catholics have generally voted in line with the nation. Still, some distinct segments of Catholics can swing an election.

Among those blocs are the 12 million or so non-Hispanic Catholics who attend weekly Mass. While less-observant Catholics have vacillated between parties and supported John Kerry in 2004, a majority of these traditional Catholics has voted Republican in every presidential election since 1992, says John Green, a senior fellow with the Pew Forum on Religion and Public Life. In 2004, 62% backed President Bush.

This time around, they seem less likely to back a Republican.

Tricia Louis, a 43-year-old Republican and mother of four, attends Mass every Sunday near her home in Withamsville, Ohio, about 20 minutes from Cincinnati. She twice voted for Mr. Bush because of his stand against abortion. In March, she cast her ballot for Sen. Clinton.

“I didn’t think the war would go on as long as it has,” Mrs. Louis said. “I still think abortion is murder, but I’ve known two soldiers who’ve been killed in Iraq. That’s murder, too.”

Now, she is weighing whether she would vote for Sen. Obama in November and has doubts that he can handle the war — as well as the economy. Ohio has lost more than 200,000 manufacturing jobs since 2000. Last year, 150,000 homes went into foreclosure, and now 1-in-10 residents is collecting food stamps.

A Pew poll taken in January 2007 found only 38% of traditional Catholics favored a generic Republican presidential candidate. An August 2007 poll showed them three times as concerned with the economy as social issues such as abortion and same-sex marriage.

“Conservative Catholics are very much in play,” Mr. Green says.

While Sen. Obama supports abortion rights, he has backed several bills to reduce unintended pregnancies and therefore the need for abortion. His campaign is hoping his record on other issues will carry the day. “He has spent an entire career bringing people together and putting his faith into action, and that’s a distinctly Catholic concept,” says Joshua DuBois, national director of religious affairs for the Obama campaign.

Sen. McCain is still establishing his conservative credentials among the religious right. In a speech at Wake Forest University in North Carolina this month, he assured conservatives he would appoint judges he characterized as strictly faithful to the Constitution, a signal they would be pro-life.

For now, wedge issues, like gay marriage and abortion, are taking a back seat, while issues like the war in Iraq, health care for the poor and concerns about the environment are keeping the conservative Catholic vote in play.

Even a small shift among Catholics in battleground states like Ohio, Michigan and Pennsylvania could swing the election.

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