Grew up in MA in a super lib family in a super lib town, I know them from the inside. And you?
No, you don't, at least not about things like this.
I grew up in Somerville, went to a Quaker school, and had (and have) anti-gun friends and family.
If you think that "presenting them with facts" is a sure way to change their thinking (which is what needs to change), I'd suggest you go to any church and try to convince the congregation that God is a fiction invented by man to make us feel better about ourselves and control the population.
You come across as naïve: great enthusiasm, great attitude, but a not really aware of the full picture.