When you're arguing with someone who doesn't have a case, that person is very likely to declare herself "offended". This is not merely because her feelings are hurt – it's also a ploy.
Screaming "That's offensive!" is nothing but a ploy. Yes, you heard it here first, few who emit that utterance are actually offended.
They just don't happen to like what you're saying.
I'll explain precisely what is going on. Liberals trade on this ploy, using it as a standard response whenever their sacred cows come under scrutiny. If they were tolerant, they would simply accept that some will espouse what we despise. If they were honest, they would simply say what they mean. But tolerance is just another ploy, and honesty, well, it has never served the ends of the left, and never less so than here. A translation of what they really mean to say will illustrate why:"I hate what you're saying, it makes me angry and you should shut your mouth! [expletives omitted]"
Of course, to exhibit such petulance would reveal their vaunted tolerance for the facade it is and demonstrate their moral inferiority. And telling others to shut-up is the stuff of neither polite society nor effective debate, so a different strategy is in order.