A government of the people is generally supposed to mirror it. That's why Congress' racial and gender makeup is often scrutinized.
But one demographic that seems to get less attention is religion — or the lack thereof. Even though roughly 20 percent of Americans are religiously unaffiliated, only one member of the new Congress is.
That makes roughly 0.2 percent of Congress religiously unaffiliated.
By comparison, 91 percent of Congress members say they're Christians. That's 20 percentage points higher than the proportion of Christian U.S. citizens.
"Unaffiliated" can mean one is atheist, agnostic or just doesn't follow one particular religion. That group is growing faster than any other religion in the U.S.
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One obstacle for a nonreligious Congress is age. Atheists and agnostics are among the youngest religious demographics in America, but you have to be at least 25 to be a U.S. representative and at least 30 to be a senator.
And that's just the base requirements. In the last Congress, the average age of a House representative was 57. That age jumps to 61 for a senator.
U.S. Rep. Kyrsten Sinema, D-Ariz., the one member of Congress who says she isn't religiously affiliated, is relatively young at 40 years old.
But it's also about more than just age. Being openly nonreligious can hurt a candidate on Election Day.
A 2015 Gallup poll found only 58 percent of Americans would consider voting for an atheist. "Socialist" was the only demographic that polled worse.
And in a Pew Research Center poll in 2014, more than half of Americans said knowing a candidate was an atheist would make them less likely to vote for that person.