Ayn Rand actually coined the phrase "argument by intimidation" where you try to frame an argument in such a way as to intimidate the other person into agreeing with you via an implied insult if they don't. "Common sense gun regulation" is (often) a form of that and you ought to (politely) snap to it and point out that you disagree as to what constitutes "common sense gun laws" and that's why you're discussing the issue.