Is it professionally bad to reveal political orientation in non-political workplace in USA?
It's really best to keep political discussions out of the workplace, especially in the USA, where opinions are so polarized and intelligent debate has become rare. Workplace relationships can easily be ruined by political disagreements, and that's the definition of unprofessional, really.
The USA has a funny relationship with communism, in particular. Announcing you're a communist would be a lot like announcing that you pee in the shower. Publicly, everyone would act aghast, even if at least some of your audience would sympathize.
Is it okay to reveal my political opinion in US workplace?
It depends on what you mean by "okay."
If you mean legal, then yes, most political viewpoints can be expressed freely as a part of your constitutional right to free speech; "hate speech" could be considered an exception, but the Supreme Court recently ruled that even that is protected under your First Amendment rights (although there are many prior cases of prosecution otherwise).
However, be sure to take into account and abide by corporate policies (often found in handbooks or orientation materials). An HR member should be able to help clarify if you have questions.
What are the consequences?
I'll answer this part by flipping the question: why should you "reveal" your political opinion? What do you stand to gain? I suppose you could try to win favor with your peers or managers, but there more impactful, substantial, and less risky ways to do that (i.e. doing your job well). You risk being rude or offensive to other people. You risk misaligning yourself with the political views of your organization. You risk ostracizing yourself (or others).
In my own experience, I've found that unless I know a colleague very well, it's just simply not worth the risk--especially when there are far better things to talk about.
When interacting with colleagues in small-talk, focus on building relationships. Talking politics yourself is a risky way to do that.
But that doesn't mean there aren't suave ways to still be involved in a discussion of politics. There are two effective strategies I've found to help handle these sorts of situations in my own workplace experience:
- Ask probing questions. You can participate in political discussions without vocally proclaiming your own opinions. Listen attentively and ask some questions. Even if you aren't intimately familiar with the latest news, you can still ask a few follow-up questions to carry a conversation. Most people enjoy talking about themselves, so let them! It's a win-win because it comes at no risk to you, and your colleague thinks better of you as a result.
- Gracefully change the subject. You don't have to be obvious about avoiding politics. Find a natural transition to other, less politicized current events. Typically, safe topics that make great bilateral conversation include sports, weather, local events or news, family, weekend plans, and so on.
Further reading: The Etiquette of Talking Politics (Huffington Post blog)