> You have the right to publish anything you like without fear of retribution from the government or anybody else.
In the US, 1st amendment freedoms only protect against government retribution. There is nothing stopping someone from misinterpreting a tweet and getting you fired, nor is there anything to prevent someone digging up what causes you support outside of work and using that as cause to harass your employer into firing you.
While true, you are protected from some types of retribution from others. For example, someone cannot kill or rob you because you express an opinion in defiance of the political or religious leadership.
You are protected from that regardless of whether you have freedom of speech.
For example, it is illegal to murder an convicted felon serving time in prison, even though such a person doesn't have the same guarantee of freedom of speech.
In the US, 1st amendment freedoms only protect against government retribution. There is nothing stopping someone from misinterpreting a tweet and getting you fired, nor is there anything to prevent someone digging up what causes you support outside of work and using that as cause to harass your employer into firing you.