People fear what they are unfamiliar with, whether that is a dangerous object, or people they don’t know.
Gun control became one of those pet topics for some reason that taken up into a liberal vs conservative stance. I think it stems from it being a Democrat platform from the days of Jim Crow. Remember the Democrats originally ruled the South, and they were the ones fighting against the Civil Rights movement. They passed laws like pistol permits the Sheriff has to sign off on (assuring only the right, safe people got the permits). There is a long, history of gun laws being targeted at minorities. So when the political shift happened and the Democrats lost the South, gained the North and became more Liberal, like an appendix, it stuck around.
It really shouldn’t be a liberal vs conservative issue. While the NRA is seen aligned with the GOP, and certainly there a lot of Republican members, it’s really a one issue org and they are more than willing to green light Democrats who are friendly to the cause.
But like the War on Drugs, we are just a few more laws from making a real difference. 
I won’t do a complete derail, but since you brought it up, the reason violence has risen and fall has had little to do with our laws (well, one could argue our current laws - not gun laws - are making things worse). Even the decrease from the crime explosion in the 90s has been a mystery as to why. Reduced lead in the environment and the legalization of abortions are two things thought to be contributes, but really the people in charge have no idea. Throw more cops at them was their only answer.
