A new poll showing that Catholics are backing off support for the death penalty was no surprise to U.S. Sen. Rick Santorum, an outspoken conservative Catholic, who says he has been re-examining his own view.

He has not become an abolitionist, and he believes church teaching against the death penalty carries less weight than its longer-standing opposition to abortion. But he questions what he once unquestioningly supported.

"I felt very troubled about cases where someone may have been convicted wrongly. DNA evidence definitely should be used when possible," he said.

"I agree with the pope that in the civilized world ... the application of the death penalty should be limited. I would definitely agree with that. I would certainly suggest there probably should be some further limits on what we use it for."

He spoke in a brief phone interview after the U.S. Catholic bishops launched a renewed push against the death penalty. Their poll showed that Catholics who attend Mass daily -- among the Americans most likely to have voted for President Bush -- also are among the most likely to oppose capital punishment.

Overall, the poll showed that Catholic opposition to the death penalty has grown from 27 percent in 2001 to 48 percent. Opposition jumps to 63 percent among daily Mass-goers -- making it 1 percent above the percentage of daily communicants who voted for Bush in 2004. Of those who say they only attend Mass on holidays, 62 percent support use of the death penalty.

According to www.ontheissues.org, which tracks voting on social issues, in 1994 Santorum voted against replacing the death penalty with life imprisonment, and in 1996 he helped to kill an effort to make it easier for death row inmates to appeal their convictions..

"I never thought about it that much when I was really a supporter of the death penalty. I still see it as potentially valuable, but I would be one to urge more caution than I would have in the past," he said.

Santorum was not surprised by the finding that daily communicants are the group most opposed to capital punishment. "Those are the folks who are most likely to listen to the pope, and the pope has been very clear about his personal opposition to the death penalty," he said.

The Catholic Campaign to End the Use of the Death Penalty was launched at a news conference with Cardinal Theodore McCarrick of Washington, DC, who spoke of his own change of heart. Born into a family of police officers, he said, "support for the death penalty was part of growing up."

Later, he said, "I was moved by the call of Pope John Paul II to be unconditionally pro-life."

He noted that the U.S. bishops have been speaking against the death penalty for 25 years.

The data consisted of two polls by Zogby International, which surveyed 1,785 Catholics in November and 1,000 early this month. The March poll showed that 31 percent strongly opposed the death penalty and 17 percent somewhat opposed it, while 22 percent strongly supported the death penalty and 26 percent somewhat supported it.

In this week's Pittsburgh Catholic, Bishop Donald Wuerl will address the topic.

"The church's opposition to the death penalty in no way minimizes the horror of the actions of those who take the lives of others, particularly when they do so in a senseless and brutal manner," Wuerl wrote.

But "we are called to recognize the face of God in everyone -- even the criminal. The destruction of human life, even in the form of capital punishment, takes away a gift that is God's alone to take. Capital punishment is irreparable."

The bishops of Pennsylvania first issued a statement against the death penalty about 20 years ago, then updated it in 2001, said Carolyn Astfalk, comunications director for the Pennsylvania Catholic Conference.

In the last legislative session, her office supported a bill to ban the death penalty for mentally retarded Pennsylvanians, but it failed because the House and Senate defined mental retardation differently.