Unfortunately, after the Civil War, when southern states had to re-write their constitutions Texas specifically cites the states right to control handguns (Jim Crow democrats didn’t want blacks to have handguns). Since this was written at a time when the seeds of “progressive thought” were starting to germinate in the US it was accepted as being in line with the US constitution.
For Texans we have a state constitution and 150 years of precedent that says the government can regulate handguns. Luckily we have a dedicated group of activists who work tirelessly to make that regulation less onerous.
Not to worry, “they” are slowly erasing the civil war so anything written with regards to something that never happened will have no validity. Or something.