Interesting, but not surprising. It’s become a biennial tradition among demographers on the day each new Congress is seated to note that the fastest growing religious group in America — the unaffiliateds, at 23 percent — is also the least represented in the national legislature. For a few years, California Democrat Pete Stark was the only unaffiliated in Congress, but he lost a Democratic primary in 2012. (Stark wasn’t just unaffiliated, he was a nontheist.) Arizona Democrat Kyrsten Sinema was elected that year, though, and has been reelected twice since, making her the only self-described unaffiliated in either chamber. How does that happen, where nearly a quarter of the general population produces 0.2 percent of America’s 535 federal legislators?

NPR has a sound explainer. Mostly it has to do with age: Unaffiliateds are disproportionately young whereas congressmen are disproportionately old, so there’s a mismatch. (Sinema is just 40.) Younger voters are less likely to vote than older ones too, meaning there are fewer unaffiliateds at the polls each November than you’d expect given how large a slice they are of the population. More significantly, though, while there are subgroups within the “unaffiliated” group for whom religious (non-)identity, matters — many of my fellow atheists are only too happy to let people know where they stand on God — the overall group is too much of a hodgepodge to produce any sort of identitarian loyalty. “Unaffiliated” includes atheists, agnostics, New Agers, and the great mass of people who believe in God, consider themselves “spiritual,” but simply don’t belong to any organized faith. With the group so heterodox, why would any unaffiliated voter see a candidate’s unaffiliated status as some compelling reason to vote for him or her? The Atlantic:

“Religiously unaffiliated” means these Americans don’t feel like they’re part of any particular religious tradition or denomination. But that includes a huge and diverse group of people. Those who formally identify as atheists and agnostics are actually a minority, representing roughly 3 and 4 percent of the American population, respectively. Others in this group, which includes roughly 23 percent of Americans, might be in the process of changing religions or feel like they have no spiritual home in a formal house of worship. They include people who believe in God and people who might be married to a spouse with a different faith background. And they include lots of people who don’t find religion particularly important or relevant in their lives.

This, above all, is why it’s suspect to suggest that religiously unaffiliated people are underrepresented in Congress: They are not actually a coherent demographic group. It makes some sense that people who have mixed feelings or don’t care about religion wouldn’t bother organizing to get more of their kind in Congress.

It’s like trying to categorize members of Congress by “brunette” hair color. A catch-all term like that doesn’t tell you much of anything about any individual’s distinct hue except that it’s not blonde or red. Although, given the political baggage that comes with the “unaffiliated” label, it may be that the term is more distinctive when used by a politician than it is when used by a member of the general population. If you’re a candidate who was raised as a Christian, say, but haven’t attended church in many years, what’s the incentive to call yourself an unaffiliated rather than a Christian? All it can do is hurt you among voters since religious voters will view you suspiciously (some people equate “unaffiliated” with “atheist”) whereas unaffiliated voters, as noted above, won’t much care. Obviously you’re better off calling yourself a Christian. The fact that Sinema insists on embracing the unaffiliated label suggests that she has a political motive for doing so, either because not belonging to an organized faith is a key part of her identity or, possibly, because she’s actually atheist or agnostic but doesn’t want to cop to that outright for fear of a backlash in the next election. Better to use the vaguer term, “unaffiliated.” (Americans are gradually getting more comfortable with voting for atheists but it’s still one of the least desirable traits a candidate can have.) All of which is another way of saying that there isn’t really one unaffiliated among Congress’s 535 members. There’s one unaffiliated who’s sufficiently invested in the idea that she’s willing to admit to it publicly. That’ll change over the next several decades as the more religious older generations are replaced by less religious younger ones.

Anyway. In lieu of an exit question, enjoy this palate-cleansing treat from a few months back featuring the newest hire by the Trump White House, Omarosa Manigault. She’ll be focused on, um, “public engagement.”