Libertarians don’t get effected by the ethics of the issue IMO, so people for drug abuse are likely to donate to Paul’s campaign, along with Soros who figures splitting votes helps Hillary (which it does).
The democrats think that paul running a third party campaign will ensure a republican victory because hillary is seen as far more pro-war than paul, and they are afraid that paul will pull off a lot more anti-war democrats then pro-market republicans, so i don’t agree it’s as nearly so cut and dried as you do.