Congress has remained majority Christian and Protestant for as long as the Pew Research Center has been tracking data, but the number of Protestants has declined by nearly 20 percentage points.
Since Pew began tracking religion in 1961 during the 87th Congress, the body has declined from 95 percent to 91 percent Christian. Protestants, while still maintaining a majority, have declined from 75 percent in 1961 to 56 percent today, Pew announced.
Of the 485 Christians in the 535-member Congress, 299 are Protestant, according to Pew's analysis of the 115th Congress sworn in Jan. 3. In 1961, Protestants numbered 401.
"Like the nation as a whole, Congress has become much less Protestant over time," Pew wrote in its report, "Faith on the Hill: The religious composition of the 115th Congress." But the percentage of Protestants in Congress still outpaces the 48 percent of Protestant adults in the U.S., Pew said in its report drawn from CQ Roll Call data.
"The group that is most notably underrepresented is the religiously unaffiliated," Pew wrote in its press release announcing the data. "This group—also known as religious 'nones'—now accounts for 23 percent of the general public but just 0.2 percent of Congress."
The 72 Baptist Congressional members comprise 13.5 percent of the body, trailing the 15 percent of U.S. adults that are Baptist, as well as the 14.8 percent of Baptists in the 114th Congress of 2015-16.
Catholics comprise 31.4 percent of the body (168), compared to the 21 percent of Catholic adults in the nation. Other religious groups in Congress are Jewish members at 5.6 percent (30), Mormon at 2.4 percent (13), and other religions affiliations less prevalent in the U.S., including Buddhist, Muslim, Hindu, Orthodox Christian, Unitarian Universalists and others. About 2 percent of members, a total of 10, did not specify a faith.
Religion by party
Christians comprise the majority of Republicans and Democrats in Congress, Pew said, with 99 percent of Republicans and 80 percent of Democrats identifying as Christian. While 67 percent of Republicans are Protestant and 27 percent are Catholic, Democrats represent more diversity in religion, Pew said.
Most non-Christian members of Congress are Jewish Democrats, who comprise nearly 12 percent of the party’s Congressional members. Among the 242 Democrats, 42 percent are Protestant, 37 percent are Catholic, with the remaining 21 percent composed of Jewish, Buddhist, Hindu, Muslim, Unitarian Universalist and religiously unidentified members. Of the 293 Republicans in Congress, the two non-Christians are Jewish.
The religious composition of the 115th Congress is largely unchanged from the previously convened body, as only 62 new members joined 473 incumbents. Among newly elected members, half are Protestant and roughly a third a Catholic. The 13 percent of new members who are non-Christian is double the share of non-Christian incumbents, Pew said.
The newest body has six fewer Christians (485) than the 114th Congress (491), Pew said; seven fewer Protestants, 299 compared to 306; and seven fewer Baptists, 72 compared to 79.
The full report is available at pewforum.org.
Diana Chandler is Baptist Press' general assignment writer/editor.