Found this through Twitter. The video quality tells me it's recent, but other than that, I think it may have been recorded in the 1970s. I can't believe these kids aren't laughing him right out of the auditorium. They don't say exactly where (or when) this was recorded, but I suspect these kids aren't there by choice.
The speaker totally confuses "getting blown" with a weed high. Reminiscent of an old Cheech & Chong routine. Hilarious.