Texas Government Code
Sec. 411.205. REQUIREMENT TO DISPLAY LICENSE. If a license holder is carrying a handgun on or about the license holder’s person when a magistrate or a peace officer demands that the license holder display identification, the license holder shall display both the license holder’s driver’s license or identification certificate issued by the department and the license holder’s handgun license.
The penalty for not complying was removed, but it’s still in the code.
Keep Calm and RTFU
If there was no penalty for making machine guns but the prohibition was still in USC, I'd have a lot of machine guns. In others words: the only reason to obey immoral and unconstitutional laws is because we are forced to.