I know there are areas with higher gun murder rates than TX. DC is a slightly unfair comparison, as you're comparing a city to a state. CA is not significantly higher than TX.

Your general point- which really seemed to be "knowing that everyone is armed in TX results in less gun violence", is easily disproven by other states with totally different laws having similar or lower gun violence rates.

To your last line- I agree with you, I don't believe crime rate should have any effect on our right to keep and bear arms. I want a complete repeal of the Second Amendment, though.