You can’t log onto social media without being exposed to someone’s opinion on politics. And, normally, I would say that’s fine. The ability to talk about what you believe and why you believe it can be extremely productive. Often, these discussions can spark progress and understanding. That being said, “freedom of speech” does not protect you from being fired for it.
In Missouri, most employment is “at-will”, which means that you can be fired for any reason or no reason whatsoever, as long as that reason is not unlawful. There is no requirement the termination of your employment be “just” or for “just cause”. There are various state and federal laws that prohibit employers from terminating employment. For example, termination of employment cannot be motivated by race, religion, sex, certain ages, disability (with certain restrictions), work-related injury, or participation in certain investigations, to name a few. Are there some glaring omissions? Definitely. Currently, a few particularly hot topics are sexual orientation and political ideology.
So what does this mean? The best advice I can offer is be aware of your social media footprint. Limit those who have access to your tweets, status, and the like by making your profile private. Not only could these things affect your current job, but they can also dissuade future employers from hiring you. The bottom line is that everybody has a right to voice his or her opinion, but that right is not one that provides us with legal protection from discrimination.