Lots of questions on this one. The first one being the most basic, is it “right” to tell an 18 year old that he/she is not old enough to make a decision about tobacco? And if it is “right”, why not go all the way to 21?Texas youth can drive and get married at 16 with parental consent, but can't legally have sex outside of marriage until they're 17. At 17 they can be prosecuted as felons and join the military with parental consent. At 17 and 18, respectively, they can get married and joint the military without parental consent. At 18 they can smoke, though Uresti's bill would increase that to 19. At 21 they can drink.
This array of age criteria will inevitably seem unfair to youth, teaching the implicit lesson that rules are arbitrary, pointless, and something they can reasonably ignore, as they see their peers doing without significant penalty. (As an aside: Don't you find it odd that Texas law would prefer you were married before subjecting you to all the various vices later in life that might undermine your marriage?)
Indeed, parents today are few and far between who can credibly lecture their kids about teen drinking, smoking, etc., without just a whiff of hypocrisy because they did the same thing - something that I'd bet dollars to donuts is true of most senators who voted for the bill. Drinking and smoking are both a significant part of American culture, for good or ill, and have been since the founding of the republic. Jennings quotes a youth who believes that extending the ban on tobacco will only add to its mystique.
For me, I've always thought the key age threshold should be when the state begins to hold you criminally culpable as an adult, which in Texas is seventeen. At that point you've assumed the full responsibilities of adult citizenship, and they should give you all the rights.
If there's some argument that youths' mental faculties aren't fully developed enough to exercise their rights, then it's unjust to ask them to bear the full burden of adult responsibility in criminal court. Whatever threshold you think is right for intoxicants, tobacco, etc., much less military service, I think should be the same as for criminal culpability - be it 17, 18, 19 or 21 - wherever you want to draw the line distinguishing juveniles from adults, it should be the same for everything.