"I never inhaled."

This is interesting but largely dependent on what drugs you consider "bad".  <sarcasm> Pot is okay.  Drinking is okay.  Heroin is not.  Cocaine only on rare occasions and off body parts!  No Acid!  Yes to sleeping pills.  Etc.  </sarcasm>  Legal things can be bad for you, so some of the talk should be geared around that.  I can imagine more of the US will legalize pot by the time my kids are in high school.  The drug discussion with them will likely be very different than the DARE stuff I had.  

I think the bottom line is that a parent is a positive and negative role model.  Children do adjust their behavior because of their parents.  Kids are also more likely to join the military if a parent was in the service.  

I agree with you bottom line, but pot can be a bit of a de-motivator at a time when a lot rides on performance (SAT scores, grades).  And no one wants a buzzed teen behind the wheel. 

I wish some teachers would weigh in.  :-)

I don't want buzzed adults behind the wheel either.  Is there an argument that years of experience/muscle memory make adults better drunk/drugged drivers?

No, but there's an argument that there will be more, not fewer, teens driving buzzed if their perception is that it's no big deal (hey, mom and did it) to get high in the first place.  Delay, delay, delay.