Fighting marijuana… or reality?, by David Nathan at CNN, is a response to David Frum and really hits this point well
Cannabis is habit forming in a small percentage of users. Marijuana intoxication impairs driving, though the risk is similar to that of drivers with a blood alcohol level of 0.05%, which is well below the federally mandated legal limit of 0.08%.
So why can’t the opposition discuss these problems realistically?
It’s simple: Because the only rational conclusion is that the dangers of pot are not sufficient to warrant its prohibition. Yet those who have an ideological opposition to legalization appear immune to reason.
Immune to reason. Yep. That pretty much says it.