You don't get to throw those out and say you're not censoring people.
"I'm trying to run a business here," is not an excuse to quash completely acceptable communication between people at work. In fact, if your worker's are incredibly divided on a topic, it may be time to have a good think about it.
Not that you should have to. Citizens United was a farce in dire need of being undone.
Either way. I get where you are coming from, and agree to a point, but enforcing a schizophrenic divide between personal and work lives isn't a very good answer either, and just creates fear amongst people that keeps them from speaking out when something is genuinely wrong.