Not really.
If you create a big series of regulations and taxes around drugs - then there will still be a huge secondary, black market.
The 'war on drugs' will therefore continue - even as you 'legalize' drugs. Double whammy.
Take cigarettes - a much milder health concern:
"the total U.S. tobacco market represented by illicit sales has grown in recent years and is now between 8.5 percent and 21 percent." [1]
So now you have to 'fight a war on drugs' - and deal with the massive health-care crisis from the considerably more people who well get hooked on opioids, barbiturates etc..
[1] http://sites.nationalacademies.org/dbasse/claj/us_illicit_to...