I work for a news organization whose social media policy cautions against expressing personal or political views that might impinge on the organization's credibility or imply bias. I know that the NLRB defends political speech in terms of workplace organizing and conditions, but what is the status of workplaces ability to curtail employees free speech on their personal accounts? Is it simply that private employers can do so freely? An excerpt: "You must not advocate for political or other polarizing issues online. This extends to joining online groups or using social media in any form (including your Facebook page or a personal blog) to express personal views on a political or other controversial issue that you could not write for the air or post [organization]."
Employment / Labor Attorney
As an initial matter, the NLRB does not defend "political speech." The NLRB defends employee action done in furtherance of "mutual aid and protection." Unless your advocacy has something to do with the terms and conditions of employment, your political speech is NOT protected in my opinion.
Because your employer is a private employer and not a public employer, I think they could terminate you for political speech.
You should talk with a reputable and knowledgeable lawyer.
Best of luck,
Howard B. Hoffman
There is no freedom of speech in the workplace; the only time that an employer cannot curtail your rights, is if the employer is a local, state, or federal government.
So short ans to your Q: Yes, they can terminate you for not following employer protocol/policy.