You are not being brainwashed, so please don't use terms like that. It detracts from what might be legitimate complaints and makes you look fringe.
You might also take a moment to reflect on whether these are isolated incidences or if you are a catalyst. I am not saying you are but a little self reflection never hurt.
If you work in a "big" place with an established HR. Register a civil and concise complaint stating that your colleges are inappropriately bringing politics into the workplace and are using their political views to create a hostile work environment. At a typical "large" company that would typically trigger at least an inquiry.
If you are at a small company, you are likely best to just move on if you can.
If you do move on then during a later stage interview you might enquire about the accepted policies of the office. Remember, many people wear their identities on their sleeves both on the left and the right so there is almost certainly going to be politics at whatever your next position is as well.
For personal context, I once interviewed with a company that asked what my favorite TV show was and I said "The Simpsons" and the interviewer followed up with a question about what radio I listened to and I told them NPR. The interviewer mutter that was good as favoring a Fox TV show would not align with the corporate culture. I declined their offer, not because I am Republican (I'm not) but because the interviewer had made it clear that politics was an important part of their culture and I did not want that kind of work environment.
I am currently working in a smaller company that is a part of a bigger conglomerate/corporation, which sometimes feel like the worst of both worlds.
I agree that using the word "brainwashed" sounds quite fringe, but I guess what I wanted to convey was that I feel like this constant, incessant seeping of one narrative makes me rather uneasy.
I don't think I am the catalyst of those events, since I hardly ever respond to them (publicly).
I set my mind on moving on, but I am really curious if there are places that are less "susceptible" to those kind of situations.