SALT LAKE CITY - In June, leaders of the Church of Jesus Christ of Latter-day Saints made a fateful decision. They called on Mormons to donate their time and money to the campaign for California Proposition 8, which would overturn a state Supreme Court ruling that permitted gay marriages.

That push helped the initiative win narrow passage on election day. And it has made the Mormon church, which for years has striven to be seen as part of the American mainstream, a political target.

Protesters have massed outside Mormon temples nationwide. For every donation to a fund to overturn Proposition 8, a postcard is sent to the president of the Mormon Church. Supporters of gay marriage have proposed a boycott of Utah businesses, and someone burned a Book of Mormon outside a temple near Denver.

"It's disconcerting to Latter-day Saints that Mormonism is still the religious tradition that everybody loves to hate," said Melissa Proctor, a professor at Harvard Divinity School.

As an indication of how seriously the Mormon leadership takes the recent criticism, the council that runs the church - the First Presidency - released a statement Friday decrying what it portrayed as a campaign not just against Mormons but all religious people who vote their conscience.

"People of faith have been intimidated for simply exercising their democratic rights," the statement said. "These are not actions that are worthy of the democratic ideals of our nation. The end of a free and fair election should not be the beginning of a hostile response in America."

Jim Key, a spokesman for the Los Angeles Gay & Lesbian Center, said gay-marriage activists' barbs are directed at church leadership, not individual Mormons. "We're making a statement that no one's religious beliefs should be used to deny fundamental rights to others," he said.

Proposition 8 opponents estimate that members of the Mormon church gave more than $20 million to the effort to pass the measure, although that is difficult to confirm, because records of campaign donations do not include religious affiliation.

For years, church leaders have tried to blunt the assertion that Mormonism is somehow out of the political and cultural mainstream. The backlash over gay marriage carries both risks and rewards toward that goal.

To support Proposition 8, the LDS church entered into a coalition with other religious organizations, including evangelical groups that have tended to view Mormons warily. It was a Catholic bishop, Mormon officials said, who requested the LDS church bring its members into the fight. Now those groups are rallying behind the embattled church.

"Being against gay marriage puts the church right in the mainstream of American religious behavior," said Quinn Monson, a political-science professor at Brigham Young University.

But the outrage directed toward the church could hurt its efforts to continue to expand.

"The backlash is going on all over the country," said Jan Shipps, a prominent scholar of modern Mormonism who is an emeritus professor at Indiana University and Purdue University-Indianapolis. "There are people who had a lot of respect for the Mormons who now say, 'Well, they're just like the Christian right.' "

That's ironic, said Shipps, given that the Mormon church has a more tolerant stance on homosexuality than some evangelical groups. The LDS has pointedly declined to state that homosexuality is a choice. And it has cautioned against programs that purport to "cure" same-sex attraction, even though Mormon theology holds that marriage is a divine relationship between men and women that continues into the afterlife.

Also, Shipps said, while the church had been riding high ever since the successful 2002 Winter Olympics here, the gay-marriage fight and other recent setbacks have forced the church to deal with skepticism over its faith and history.

First there was former Massachusetts Gov. Mitt Romney's unsuccessful run for the Republican presidential nomination. Mormons were shocked that Romney's LDS faith was a source of discomfort for some voters.

"Latter-day Saints were just amazed to think there was such bigotry in the country," church spokesman Michael Otterson said.

And a raid on a polygamous breakaway sect in Texas this spring was a reminder of the church's use of multiple marriages in the 19th century, even though the LDS has long renounced polygamy. "That whole story in Texas was probably much worse for the church's image than Proposition 8," Monson said.