There is a saying, the devils greatest trick is making you believe it doesn't exist. Similar to anti gun nuts. The anti gun people in powers greatest trick is making the weak minded fight for them.
From a pure logic standpoint, all it takes is for someone to offer an example (state, city) with a high percentage of concealed/open carry going on -- with or without the need for a license or permit -- that also has a lower number of gun-related murders. Justified self-defense shootings resulting in the death of the threat/s need to be excluded.
That, or one example of anywhere with stricter gun laws (CA, NY, Chicago) that has a higher rate of gun murders than HI.
Using a single variable to explain any observation as complex as crime is ignorant. But, that's how they convince the uneducated.
There was a study that said there is NO CORRELATION between the number or type of gun laws in a state and the number of gun-related murders. There are just too many examples that disprove the correlation to believe laws stop criminals with guns.
Look at NY. They were arguing to the SCOTUS that their gun laws were needed for "safety," yet they just had a mass shooting at a market. Kind of disproves their point, huh?
Politicians are adept at telling us "The law will solve X, Y, and Z". There's no empirical data or surveys that PROVE such laws have any effect on X, Y, Z. It's what they have to say to justify passing the law. And they never seem to want to revisit the law and evaluate the impact it had on X, Y or Z -- because they rarely solve any real problems. Most laws just impose more fines to raise revenue for the state/city/county.