Right, people should advocate for whatever politics they want... just not at work. The issue you identify is a government one, not an individual workplace one. Even something like that is too much burden to put on your fellow co-workers to have to advocate for or pick a side.
"Even something like that is too much burden to put on your fellow co-workers to have to advocate for or pick a side."
The manager has to pick a side- they can choose to fire an LGBTQ person for being LGBTQ or not. A co-worker can choose to treat a co-worker differently if they happen to be LGBTQ. An employee who is married and gay may need to choose to leave off their wedding ring and to not allow their spouse to enter healthcare with them, because they cannot risk their jobs by being found out by HR as a homosexual.