IOW-you will get charged with murder in Texas if you walk in, find your wife sleeping with another man and you kill them both. In most states thats second degree murder. Not in Texas. Thats just murder. However, In Texas, passion can be argued as a defense at the punishment phase.
So, what happens in Texas is you get a murder charge and a sentence that looks like a CNH or manslaughter conviction due to circumstances.
I was referring to the difference in capital murder and murder being akin to 1st and 2nd degree...
However I do see what you mean by the sentencing phase being where the hairs are split.