Where "is the constitutional grant of authority to ban mere possession of cocaine today?"

Does the Constitution allow jury nullification? Thomas R. Eddlem certainly thinks so. As the Cato Institute's Tim Lynch details in a superb post, Eddlem was booted off a jury for daring to question federal drug laws:

The jury sent a note to the trial judge with the following query: Since the Constitution needed to be amended in 1919 to authorize federal criminal prosecutions for manufacturing and smuggling alcohol, a juror wanted to know from the judge where "is the constitutional grant of authority to ban mere possession of cocaine today?"

[…]

[District Court Judge William G.] Young tried to assure the jury that the federal drug laws are constitutional because the Supreme Court has interpreted the commerce clause quite expansively. When the jury sent out more notes about a juror that wasn't going to sign off on an unconstitutional prosecution, Young halted the proceedings to identify the "problem juror." Once discovered, that juror was replaced with an alternate-over the objections of defense counsel. Shortly thereafter, the new jury returned with guilty verdicts on several cocaine-related charges.

So who's right, Judge Young or citizen Eddlem? Here's legal scholar Randy Barnett:

There is little question that, at the Founding, jurors were triers of both the law and the facts. In essence, this provided a popular check on an overreaching legislature and a supine judiciary, although a check that would only operate on a case-by-case basis. A jury could find that a statute was unjust generally, or only as applied in the particular case. This would affect the general enforceability of a statute only if many juries agreed.

For more on Eddlem and his jury nullification, check out this Boston Globe story. And don't miss the accompanying photo, complete with a copy of Judge Andrew Napolitano's A Nation of Sheep on Eddlem's table.