No one was fired because who they loved.
This person was fired because they brought bad publicity to the company because of his association with a hate monger.
Maybe it can be disputed in a wrongful termination case.
And he may win.
But there is a lesson that your social media can affect your job and your spouse's job.
You can take the chance of getting fired and suing for wrongful termination but maybe you'd bet better off not saying crap on social media.
For example, I know better than to publicly post the views that I anonymously post here, for my professional sake and that of my wife.