It doesn't mean an employer has to tolerate you on the payroll if your bias is the kind that will interfere with doing your job.

This isn't a free speech issue. It's whether or not you can count on a cop who posts consistent anti minority or misogynist crap on social media can possibly do his job in a professional manner if either group is involved.

No one is suggesting jailing cops for posting hate speech. That would be a violation of the first amendment.