A Gallup analysis released on Friday found the U.S. partisan gap in religious identity is widening.

In an aggregate of five Gallup surveys conducted from May 2021 to May 2023, 26 percent of people who say they have no religious identity “identify or lean towards the Democratic party.” In comparison, the aggregate found that only 11 percent of those who profess no religious identity “identify or lean towards the Republican party.”

“Looked at differently, across the combined 2021-2023 data, equal proportions of Americans identified as Democratic or Democratic-leaning (46%) or Republican or Republican-leaning (46%),” the analysis read. “Yet, the group of Americans who are religious nones split 63% Democratic versus 26% Republican — far different from the population at large.”

Twenty years ago, only 5 percent of Republicans and 7 percent of Democrats cited no religious identification, just a two-point gap. By 2013, those numbers had risen to 6 percent of Republicans and 19 percent of Democrats.

“The key takeaway is the possibility of a spiral or self-fulfilling prophecy effect — the idea that as religion becomes identified with Republican and conservative politicians and positions, it will continue to drive Democrats and liberals away from religion, amplifying the pattern by which Republicans increasingly dominate the group of those who remain religious,” the analysis read.

Other findings in the analysis included Republicans being more likely than Democrats to identify as Protestant at an 18 percent gap.

“By contrast, the percentage of each party identifying as Catholic is roughly equal. Unlike Protestants, Catholics have maintained a roughly stable percentage of the American population over time and, as seen here, have remained largely immune from the partisan divide evident among Protestants and nones,” the analysis continued. “Explanations for this phenomenon are tied up with — among other factors — the impact of immigration on the composition of the Catholic population.”