"Accumulated evidence" is no more an enumeration of power than "feelings". Who's using "sleight of hand" and "sloppy logic" here? The wailing about "accumulated evidence" is calculated to evoke an emotional response (fear) and stop you from looking at the actual, enumerated powers in the Constitution and asking whether the drug war is covered by the original intent of those powers.
Accumulated evidence is just that. Data. Evidence.
I can appreciate your attempt to avoid dealing with the harsh externalities of drug use by dismissing it all as “feelings”.