7 states have laws on the books making it illegal to run for office as an atheist. Could put a monkey wrench in a campaign for office.

Sinema from Az.

I would be delighted if we could just have an openly agnostic legislator.

Unless you want the entire house to look like the Republican side of the House, then the non-believers need to stay in the closet, just like the non-believer Presidents have.

I think in politics and in all walks of life people don't want the distraction of dealing with the demonization around what is at the end of the day a very insignificant and prosaic aspect of your life. It says nothing about the morality, ethics, integrity, diligence, honor, dignity, love, empathy, expertise, etc. that you bring to the table. And so while on one hand people want to see their legislators reflecting their [un]beliefs, there's a very real sense in which atheism isn't an adequate expression of that to begin with.

It's no different than that theists aren't necessarily good people just because they're theists; in fact, quite often the very opposite. The issue is not what you blather on about, it's how you actually behave and treat others that matters -- or in the realm of politics, it's all about policy and your personal integrity and fidelity to your policy positions. And so casually identifying as an atheist is giving away your power to people who want to try to define who you are, and getting away from what you should actually be judged by in terms of your effectiveness or how you'll actually represent people.

As a concrete example, if I still lived, as I once did, in Kirsten Sinema's district, I would want to know way more about her policy positions and her communications skills and tactical abilities than about her god-beliefs or lack thereof. I would prefer someone with policy positions and tactical plans I can get behind, over someone who just so happens to think the same things about deities as me. Even though if she happened to share my lack of god-beliefs, that would be a Good Sign, it's far from everything.