I could just look at the chart and see it was wrong. First off, the "high incidents of gun violence" highlights the northern portion of Maine, which is barely populated.
Chicago isn't even on that map, neither is the Dallas Fort worth area. I'm not sure of the crime rate of Dallas, but I'm sure it would show a little blue.
Secondly, someone did this same map when Bush ran Against Gore, claiming the ratio was like 13-6 in the voting demographics...
But it turned out it was more like 6-4.
However, the general gist of the map IS accurate. Democrat strongholds are the cities, and the cities have a much higher crime rate.
America has fought wars across the globe, because we kept our firearms while others let dictators take theirs...