> The last study I read found that it’s more harmful than cigarette smoke and that’s a serious bill.

This was an intentional distortion of the study (if we're talking about the same one) created by the press releases of antidrug organizations. The headlines all screamed that pot smoke was more dangerous than cigarette smoke, and you had to dig to the third paragraph of the articles (where facts go to die) to find out that what the study actually suggested was that (cigarette smoking + pot smoking) was worse than cigarette smoking alone.

IIRC, it also focused on people who were smoking their pot mixed with tobacco, and suggested the reason for the damage was that people hold in pot smoke far longer than they normally hold in cigarette smoke, so more of the cigarette smoke settled rather than being exhaled.