The 10th Amendment to the Constitution states:"The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people."

What this means is that the powers of the Federal government are clearly defined and finite. They may not appoint themselves more powers. Any powers not given to the Federal government are to be handled by the States or the citizens.

Now stop and think how many powers our Federal government has that aren't given to them by the Constitution:
Gun control
Drug Enforcement
Education
Health Care
etc. etc.

So, from a Constitutional standpoint, anyone arrested and convicted by a Federal law enforcement agency or court for drug offenses is being arrested, tried and held illegally.

The Constitution clearly defines what the Federal government may and may not do. Our elected officials have been systematically siezing these powers right under our noses.
Of course, we're to blame because we let them do it.