I’ve been doing immigration law enforcement in Arizona for the past 10 years and I’m always polite. The aliens that I have removed from the US have never mistaken my politeness with weakness.
Exactly my point. And if they did, well then, that would be their mistake.
Being polite is a good personal policy. If I do my best to be polite to people and treat them respectfully, even if they don't respond in kind, I can sleep well knowing I have done my best and acted appropriately.