The point the liberals miss is this; if reducing the number of guns reduces crime how come there is more crime in Chicago than in areas that don't have gun control? If guns are the source of evil you'd expect that crime would go down, albeit not to 0, when you keep people from having guns but instead crime has increased in Chicago.
Maybe because the only people that are disarmed and undefended by gun control are honest citizens. If you can buy illegal drugs why does any sane person think that criminals won't be able to buy illegal guns? But if the crook thinks his victims won't be able to defend themselves he's going to be more likely to try and attack or rob them thereby increasing crime. Further if you're a crook and you want to take someone out knowledge that he's less likely to be armed will tend to embolden you.
The problem isn't things; it's people. People kill people; guns are just something they use. But liberals don't want to punish killers, unless they're white folks who have killed black folks, because liberals constantly push to make it harder to convict criminals and easier for those criminals to get out of jail early in those cases where the criminals are convicted.
Only a liberal could think that reducing the number of guns in honest citizens hands will reduce violence but allowing violent criminals to walk the streets won't.