Last week, Mitt Romney gave an emotional speech on the Senate floor, explaining why he was voting to impeach President Trump. “I am a profoundly religious person,” he said. “My faith is at the heart of who I am. I take an oath before God as enormously consequential.” Romney, a member of the Church of Jesus Christ of Latter-day Saints, referenced his duty to the Constitution and to God as reasons that he must vote according to his conscience. Utah’s junior senator told McKay Coppins of The Atlantic that a verse of Mormon scripture helped guide him during the trial: “Search diligently, pray always, and be believing, and all things shall work together for your good.” He also recited a line from an LDS hymn: “Do what is right; let the consequence follow.”

Romney became the first senator in U.S. history to vote to convict a president from his own party. His actions and the public reaction to his vote are evidence of the unique role that Mormonism plays in politics and public life. They were also the latest sign that Mormonism has been in an imbalanced relationship with the Republican Party for a very long time.

The social media response was swift. Voices on the left hailed him as a hero. (Many of those same voices, though, were quick to be critical of his faith during his 2012 presidential run.) His critics this time responded with the usual Mormon mockery, invoking magic underwear, cracking jokes about believing in angels, and the like—all standard insults and misperceptions that Latter-day Saints have endured since their antebellum origins.

Fox News’ Brian Kilmeade’s comments, though, deserve special attention, given his platform and place within conservative media circles. On his morning television program “Fox & Friends,” the host told his national audience that Romney should have kept his faith out of the decision. Questioning how Romney could use his faith as a reason for voting for Trump’s removal, he incredulously asked, “My faith makes me do this? Are you kidding? What about your faith and this case meld together?” He concluded, “That is unbelievable for him to bring religion into this.” It was an odd admonishment for a channel that touts the values of conservative Christians—especially white evangelicals—quite often, and that generally accepts religious justification for supporting Republican Party platforms. But the Fox anchor’s comments reflect the tenuous relationship among Mormons, evangelicals, and the Republican Party over the past century and a truism it illustrates: Mormons who vote Republican are useful. Mormonism, if wielded against GOP talking points, is not.

In 1904, the United States Senate convened hearings to ascertain whether Reed Smoot, Utah’s junior senator and an apostle for the LDS Church, could hold his seat in Congress. Senate Republicans, largely self-identified Protestants, questioned whether Smoot could serve the people of Utah in an unbiased matter, given his connection to his church, which they argued, had never followed through on promises to Americanize. These Republicans viewed Smoot as the LDS Church’s puppet, incapable of making moral decisions because of his professed faith, which they viewed as a “false” religion. Kathleen Flake has shown in her book The Politics of American Religious Identity that Smoot and the Republican Party came to a political agreement during the trial’s three-year duration. Smoot would support their policy platforms and work to flip Utah’s residents to the Grand Old Party. In return, they would stop calling LDS leaders to answer questions about their church on the Senate floor. The deal worked for both sides. However, there’s no question as to who wielded the most power in the relationship. Mormons acquiesced to a national political party and won political influence. Republican Party leaders gained a crucial electoral constituency and did not have to recognize Mormonism as a religion on the same level as Protestant Christianity.

Utah’s white Mormons became more Republican over time. The Beehive State and its Latter-day Saint citizens did not align strictly with Republicans or Democrats through the mid-twentieth century, despite some LDS leaders who identified the New Deal’s social safety net as bad for the nation’s spiritual health. The partisanship expressed by individual leaders did not stop Latter-day Saints from voting for Franklin Roosevelt in each of his four presidential campaigns.

After World War II, however, the elevation of LDS Apostle Ezra Taft Benson to Dwight D. Eisenhower’s cabinet signaled a change in the white Mormon electorate. Latter-day Saints in Utah, the majority of the state’s citizens, latched onto Republican platforms and cemented their place in the American mind as fervent Cold Warriors. Many Mormons joined white evangelicals in opposing integration and the civil rights movement while supporting free-market fiscal policies. In 1964, they rejected Republican presidential candidate Barry Goldwater, but that election marks the last time that a majority of Utahns or Latter-day Saints voted for a Democratic presidential candidate.

Beginning in the mid-1970s, white evangelicals courted white Mormons as they built the electoral infrastructure that became the religious right. As historian Neil J. Young has documented in his book, We Gather Together: The Religious Right and the Problem of Interfaith Politics, this outreach came in spite of Mormon beliefs, not because of them. Jerry Falwell Sr. and others did not stand up for Latter-day Saints who were roundly mocked by evangelicals in the press and on television—so long as those making light of Mormonism did not risk votes.

The thinking seemed to be: Mormons were great to help secure the Republican platforms championed by white Christians, but Mormons were decidedly not Christian. And yet, evangelical accusations of heresy did not stop Mormons from voting Republican. White Mormons became full-throated supporters of the religious right and minority members of the Moral Majority. The GOP fought for their political goals, especially around rejecting the Equal Rights Amendment and same-sex marriage. LDS Church members had put up with name-calling for their faith’s entire history; perhaps they could put up with religious besmirching to attain higher goals.

Fast forward to Mitt Romney’s appearance on the national political scene. In the lead-up to the 2008 presidential election, GOP candidate and former Baptist pastor Mike Huckabee seemed to malign Mormon theological beliefs when he asked The New York Times: “Don’t Mormons believe that Jesus and the devil are brothers?” He later apologized for the misunderstanding. Despite the fact that Romney failed to get the GOP nomination and many Republicans did little to accept Mormonism, Utah’s Republicans, of whom a majority are white Mormons, voted for the GOP by a margin of 62 percent to 35 percent in the general election.

The same held true of Romney’s 2012 campaign. Robert Jeffress, a megachurch pastor and now a stalwart champion of Donald Trump, rejected Romney, saying that he belonged to a cult. In contrast, the Billy Graham Evangelistic Association took Mormonism off its list of cults in October 2012 after the evangelist met with the presidential candidate; indeed, the list of cults was scrubbed from the organization’s website entirely. In doing so, Graham—or at least his team—did not signal an acceptance of Mormonism so much as the view that political alignment was more important than theology in presidential elections.

Romney’s interaction with the Republican Party, in many ways, highlights the symbiotic relationship that his church and the GOP have had over the past hundred years. But it may not always be so. Rising generations of Latter-day Saints identify as more liberal than their parents and grandparents. Some support democratic socialists like Bernie Sanders. (It remains to be seen whether the Democratic Party or voices on the religious left will court their vote.) LDS Church leaders have also broken with many political conservatives by issuing official statements in favor of protecting immigrant “Dreamers” and the need to practice environmental stewardship.

Many American Latter-day Saints, especially younger ones, also hold unfavorable views of Trump (though not necessarily of Republican Party platforms). In 2016, Trump was not as popular in Utah as he was in other red states—a sign that perhaps Romney will not suffer much for his impeachment vote among his mostly Mormon electorate. And yet, since the impeachment trial, Trump’s approval rating in Utah has climbed.

Romney’s announcement closed with a reminder that he knew his vote would not remove Trump from office. “Voters will make the final decision,” he said, echoing the president’s lawyers. Romney turned toward the responsibility he had to his family, in a way that felt very Mormon: “I will tell my children and their children that I did my duty to the best of my ability.” After decades of Republicans counting on Mormon voters, a GOP senator representing the state with the most Mormon voters crossed party lines. In a sense, Romney treated the Republican Party as it has treated Mormons for years—differences could be harmonized until religious feeling, practice, and affiliation demanded otherwise.

The Republican Party may not take Mormon beliefs very seriously, but it does count on Mormon votes. The relationship will likely remain one-sided unless more Latter-day Saints defect to the Democratic Party, which has not pursued their support in earnest. Mormon voters could be valuable constituents for either political party—if only party leaders value their theological convictions as much as they do their votes.

Joseph Stuart is a Ph.D. Candidate in History at the University of Utah.