But thats the problem. Nowadays, saying "the idea of sanctuary cities has been taken too far; nations should have full control over their borders; immigration laws should be enforced" would not be a safe thing to say at my workplace.
Then I think your workplace is in the wrong in this situation. Reasoned discussions not based in bigotry/xenophobia/etc, where both sides are respectful, should definitely be acceptable at work -- they definitely are at mine.
