[green iguana]

As it stands the Federal government has no power to prohibit drugs unless they cross state borders

As it stands now, the Federal gov't can prohibit drugs all it wants since drugs that don't cross state borders are indistiguisable from those that do.

[Know your rights]

As it stands now, the Federal gov't can prohibit drugs all it wants since drugs that don't cross state borders are indistiguisable from those that do.

Backward. If they don't want to invest the effort to determine which drugs have crossed state borders (by, say, patrolling those borders) then the Constitution requires them to keep their noses out of the matter.