Robert Mueller, director of the Federal Bureau of Investigation, never looked wearier or more at a loss than when he tangled last week with 9th District congressman Steve Cohen of Memphis on the issue of whether marijuana can be considered a "gateway" drug, leading to experimentation with harder drugs like cocaine, heroin, and methamphetamnes.

In this CNN video (below) of a Judiciary Committee hearing last week, Cohen presses his interrogation of Mueller on the issue of whether use of marijuana — the legalized medical use of which Cohen is a proponent of — leads to dependence on the more dangerous drugs. Mueller fumbled with the question, acknowledging at one point that he could cite no death attributable to marijuana use.

In the end, Cohen hazarded an answer in the negative to his own question, suggesting ironically that milk leads to beer which in turn leads to the use of bourbon.

Here's part of how it went: