PROVO — Prayer became a political football on Sunday after Devin Patrick Kelley shot and killed 26 believers in a Baptist church in Texas.

First, President Donald Trump and House Speaker Paul Ryan, both Republicans, tweeted about prayers for the victims and their families. Then Sen. Elizabeth Warren, D-Massachusetts, tweeted back, "Thoughts & prayers are not enough, GOP," a sentiment repeated by many others.

In an editorial column sarcastically titled "How dare the GOP pray for Texas" in Monday's Wall Street Journal, former George W. Bush speechwriter William McGurn defended the religious right. "In short," he wrote, "if you are Republican praying instead of passing gun control, you've got blood on your hands."

But at BYU on Tuesday, Notre Dame political science professor David Campbell said that the political movement known as the religious right would do better to look itself in the mirror than express outrage when Democrats, liberals and progressives rail against religious expressions in the political arena.

In fact, Campbell said that the rise of secularism in the United States is a direct consequence of a backlash against the close ties between the religious right and the Republican Party. And he said the divide is worsening during the Trump administration.

"If my argument is right," Campbell said, "there’s this tremendous irony that the religious right was formed to advance the cause of religion in the public sphere, but it has actually contributed to a decline in religious affiliation in American society."

Campbell's keynote address kicked off the BYU Wheatley Institution's third biennial Conference on Religion in the Public Sphere at the Hinckley Center on campus. He used data from the Faith Matters Survey that he and Robert Putnam commissioned for their book, "American Grace: How Religion Divides and Unites Us."

"When many Americans look out at religion and see it as tightly intertwined with one political party, and then they decide that religion is not for them, you would expect to see exactly what we've observed in American society, the growth of secularism or a turn away from religion," Campbell said.

A BYU graduate and a Mormon, Campbell is an expert on religion, politics and civic engagement who co-authored "Seeking the Promised Land: Mormons and American Politics."

He said people who are leaving behind their religious affiliations are largely people with center-left political views who become disillusioned by their perception of their religion's tie to political agendas on the right.

"We find that the increase in people who say they have no religion is almost exclusively driven by people's political attitudes and is almost entirely concentrated among those who are either at the center or left of the political spectrum," Campbell said. "In other words, it is the politics that is driving the turn away from religion and not the other way around. It's not that you start out secular and then become a Democrat or political leftist. Instead you start out on the political left and then you pull away from religion. And that is more concentrated among those who see this connection between religion and partisan politics."

Campbell said a recent dramatic shift by white evangelical protestants has spurred increased disillusionment on the left toward religion.

In 2011, 30 percent of white evangelical protestants said an elected official who commits an immoral act in their personal life can still behave ethically and fulfill their duties in public and professional life. That number jumped above 70 percent in October 2016, just before the presidential election and just after the Access Hollywood tape surfaced with Trump using vulgar language about women.

Campbell said the shift allowed evangelical voters to support Trump and called it a "striking example of how increasingly Americans put their politics before their religion or how their politics shape their religious views."

"In today's environment, religion has increasingly come to be associated with partisan politics," he said. "Not just with partisan politics but with one party in particular, and now with one faction of that party, the Trump-Bannon element of the party rather than the Bush-Romney-McCain wing of the GOP."

The consequences are dire.

"I would like to suggest," Campbell said, "that when religious believers put politics ahead of their religion they risk betraying their own principles, they risk ceasing to speak prophetically in American society and they risk creating exactly the sort of backlash against I have described."

Campbell made clear at the start of the lecture that religion is an engine for civic engagement. In fact, he said, the Faith Matters survey found that the more religious one is, the more likely one is to have solved a community problem, to vote frequently in local elections, to be a member of civic associations, to be a leader in those associations and to attend their meetings frequently.

Religion also has been a major driver of political change in America.

"It is hard to think of a major social or political reform across American history that did not have religious roots," Campbell said. "And that came from all points of the religious spectrum, left, right and the center. Religion's influence has been most powerful, I would suggest when it has risen above partisanship, such as the Revolution, abolition, women's suffrage, civil rights."

Campbell also showed that religious influence ebbs and flows in American society. While it is ebbing now because of the backlash against the religious right, many who have left religious affiliation maintain a belief in God or are open to the idea. Religion's influence therefore may rise again, he said.

"I would suggest that will only happen if believers put their religion and not their politics first," Campbell said.

He suggested that one way to make progress would be to support religious pluralism.

Meanwhile, during a question-and-answer session, Campbell said Democrats have failed to capitalize fully on the backlash against the religious right.

People on the right become more religious over time, he said, causing real dilemmas for the Democratic Party.

"This is interesting and not acknowledged," he said. "Actively secular folks are the base of the Democratic Party, but the Democrats haven’t figured out how to capitalize and motivate that group without alienating moderately religious voters."

Student delegates to the conference from around the country arrived Tuesday and will spend the rest of the week at BYU's Aspen Grove camp above Sundance participating in roundtables with experts on religion in the public sphere.

Maddie Thompson, 20, a junior in theology and peace studies at Notre Dame, said Campbell's lecture provided a strong start to the week.

Thompson, who is from St. Louis, is participating in a roundtable on the religious "other" and Jewish civil society, She will spend next semester in Jerusalem on study abroad.

"I'm looking for action items," she said. "Little pieces of hope and policy changes to help each individual. To have the problem named is one thing. To improve it is another."