WASHINGTON – Republican presidential hopeful Mitt Romney on Saturday denounced “poisonous language” against faiths as he grappled with a flare-up over religion sparked by a prominent supporter of Texas Gov. Rick Perry, his rival. Perry steered well clear of that simmering issue and pushed another hot button instead: Social Security.

Romney, in remarks to the Values Voters Summit, a gathering of cultural conservatives in Washington, did not directly confront the words of a prominent Perry supporter who called Romney’s Mormon faith a “cult.”

Indeed, Romney was criticizing another speaker at the meeting who is known for anti-Mormon and anti-Muslim rhetoric, and who followed him on stage.

But his cautionary words served as notice that attacks on religious faiths should, in his view, be off the table. He appealed to the social conservatives to support a presidential candidate who has the best record on the economy.

Until now, Romney’s Mormon faith and Perry’s evangelical Christianity were secondary to a GOP primary focused on who can best fix the country’s economy. Questions about his faith plagued Romney’s 2008 presidential run, but he had been able to keep them at bay so far this time.

That changed when a pastor who introduced Perry to cultural conservatives called Mormonism a “cult” and said Romney is “not a Christian,” forcing Perry to distance himself and Romney to respond. The back-and-forth suggests the primary race — with a field finally settled and just three months before voting begins — has moved into a more aggressive phase. And it illustrates that Perry’s very public religiosity and long history with evangelical Christian leaders won’t remain on the sidelines of the presidential race.

But Perry, campaigning Saturday in Iowa’s staunchly conservative northwest, barely touched on religion at all. In stops at Sioux City and Orange City, he never mentioned Mormonism, addressed Romney by name, or even Christianity, for that matter.

Asked by Republican Steven Bernston what books have most influenced him, Perry mentioned only one: the work of conservative economist Friedrich Hayek.

Bernston, a corn and beans farmer from Paullina, later said he was surprised that Perry didn’t at least mention the Bible.

“I don’t think he’s a reader,” Bernston said in an interview, noting that Perry used the question to switch to previous statements about his opposition to government efforts to stimulate the economy.

Perry waded back into Social Security instead, a tricky issue for him after he roundly criticized the popular entitlement in his book and his Republicans rivals piled on against him. Responding to a question in Sioux City, he said “it makes sense” to increase the eligibility age for benefits and it may be time to reduce those benefits for the wealthy, a process known as means-testing.

In each of four Iowa campaign stops over two days, Perry took questions from voters, and none from reporters. None of the questioners mentioned Mormonism or asked overtly religious questions.

On Friday, Robert Jeffress, the lead pastor at First Baptist Church in Dallas, introduced Perry as “a committed follower of Christ.” Perry thanked him, and said Jeffress had “hit it out of the park.”

Afterwards, Jeffress told reporters Romney was “not a Christian” and that Mormonism is a “cult.” Jeffress had repeatedly made similar comments during Romney’s 2008 campaign.

Mormonism sparks concern among evangelical Christians, a critical bloc of voters in the Republican primary.

At an event in Iowa later Friday, Perry was asked if he believes Mormonism is a cult. “No,” Perry said.

On Saturday, Romney answered Jeffress’ charge: He praised former Reagan official Bill Bennett, who spoke ahead of Romney at the conference. “You did Rick Perry no good, sir, in what you had to say,” said Bennett, denouncing Jeffress for “bigotry” against Mormons.

“Speaking of hitting it out of the park, how about that Bill Bennett!” Romney said as soon as he took to the podium.

It was a subtle but unmistakable rebuttal.