I would not discount the effect of social media. Lies told broadly and often enough become truth. My facebook and twitter includes people who are anti gun and the messaging is relentless.
I have a score of connections who send a couple of messages a week on murder news stories with "maybe he (insert perp) was 'standing his ground'," along with "where was the NRA's 'good guy with a gun'?"
Reductive slogans and idiot talking points repeated often enough make people think it is consensus. Studies show over and over that following consensus is a factor, and in many cases the sole factor, in adopting an opinion.
The majority of your fellow citizens think gun murder is up when it has plummeted. Never underestimate the power of herd idiocy.