New research provides evidence that the personal religious beliefs of United States Senators influence their legislative behavior. The study was published in The Journal of the Scientific Study of Religion.

“I became interested in the topic of the influence of religion on politics after moving to the US from Israel. What I found particularly interesting is how the US had seemed like a country in which there is a clear separation of church and state, and yet religious discourse still dominates many aspects of its politics,” said study author Daniel Arnon of Emory University

“I became curious whether the avenue through which religion entered politics was primarily from the bottom-up — through constituents’ demands and political representation of religious constituents — or whether the mechanism was more top-down — through the religious preferences of the legislators.”

“Previous literature had shown that legislators’ religious traditions were associated with specific voting patterns, but I was curious whether other facets of their religion, like their theological beliefs and religious participation, might also change voting patterns. Furthermore, I wanted to know whether religious preferences in the legislature impacted broader policy areas than those narrowly defined as “religious issues.'”

Arnon examined a number of sources to create religious portfolios for 150 senators during the 110th to the 113th sessions of Congress. He found that the lawmakers’ religious beliefs were associated with their legislative behavior, and this relationship was still significant even after controlling for the senators’ personal and ideological characteristics.

“The religious preferences of senators are associated with voting and policies in the Senate, across all issue-areas: economic, social and foreign policy,” Arnon told PsyPost.

But is this because more religious constituencies tend to elect more religious senators, who in turn push legislation that is aligned with the dominant religious beliefs of their state? Arnon found evidence that this didn’t entirely explain the situation.

Senators with more traditionalist religious beliefs tended to push more conservative legislation, even if their constituencies weren’t as religious. Senators were considered “traditionalist” if they held literalist interpretations of religious texts and viewed God as commanding or restricting their actions.

“Even when controlling for the senator’s religious constituency, their personal religious preferences still matter,” Arnon explained. “Specifically, I find that the senators’ religious tradition (Catholic, Jewish, Protestant, etc) is not the main religious driver of voting in the Senate, but rather that the most important religious factor is their religious beliefs — whether traditionalist or more moderate and progressive.”

“The bottom-line is that while church and state are formally separated, religious legislators are still driven by their religious beliefs when voting in the Senate on all issue areas. This mechanism circumvents the formal separation of church and state and brings religion into politics through the back door.”

While religious traditionalism was found to influence senators, the study found no evidence that their level of religious engagement was associated with their legislative behavior.

“As other research has shown, the religious landscape in the US has been changing in the last few decades. I examined a very specific period with the data I have (2007-2015), and I do not know whether these findings necessarily generalize to past or the future,” Arnon added.

The study was titled: “The Enduring Influence of Religion on Senators’ Legislative Behavior“.