People get emotional over things that are meaningful to them. I read, that Joe Biden made a remark that he is aware that the rifles targeted for elimination by Feinstein are not the main problem in killings. Politicians seem worried about their constituents mental trustworthiness (not surprising as they actually voted for them!!!) and therefor want to disarm them.
However, just how reliable gun owners mental stability really is (especially when compared to our elected leaders) is obvious when one sees, that not even one of the more than 40 Million gun owners has attempted to 'take out' any of the most threatening gun haters (Bloomberg, Feinstein etc).