Maybe, but not because it got a snarky mention on an animated TV series.  This CBS report on 4/20 Day leads with Family Guy‘s plot line as a major broadcast media statement and a cultural shift:

On yesterday’s episode of Fox’s animated sitcom “Family Guy,” one of the main characters – a dog named Brian – is arrested for possession of marijuana. He subsequently goes on a mission to legalize the drug, at one point earnestly arguing that it is only outlawed because William Randolph Hearst wanted to keep hemp production from hurting his paper interests in the 1930s.

Yes, the argument was articulated by an animated dog. And yes, the response from one of the other characters was, well, a fart. But still: Last night, a serious argument for marijuana legalization was articulated on a major American cable network during prime time.

It’s safe to say we’ve come a long way from “Reefer Madness,” the church-financed 1936 anti-marijuana propaganda film (also known as “Tell Your Children”) that suggested marijuana leads to murder and depravity. …

But there does seem to be a clear movement toward greater acceptance of marijuana use; positive representations of pot smokers are increasingly popping up on television (The Sarah Silverman Program, Real Time With Bill Maher) and in movies (Pineapple Express, The “Harold And Kumar” series.)

Tommy Christopher sardonically follows up with a quote from Scooby-Doo: “Zoinks!”

Brian Montopoli then cites Pineapple Express and Harold and Kumar Go To White Castle as evidence that a recent groundswell of support for marijuana legalization has begun.  It’s cute in the same way that every generation of teenagers think they’ve discovered sex.  Marijuana references in movies have been almost unendingly positive for decades now, and usually shown being smoked not by babbling potheads but mainstream, sympathetic characters.  Animal House did it over 30 years ago (1978) with a college professor and three of the protagonists from the film, for one example, and it wasn’t particularly controversial at the time of its release. Blazing Saddles had its two main characters, Sheriff Bart and The Kid, toking up in 1974 as a demonstration of how cool they were.  Both movies have been on network TV for decades.

That’s always been the contradiction with marijuana prohibition, as opposed to prohibitions on other substances.  Most people don’t consider it that big of a threat, not at all in the same class as heroin or cocaine.  It’s not even as deadly as alcohol; people die every year from alcohol overdoses, something that just doesn’t happen with marijuana.  While it retains enough stigma to keep a significant number of people against outright legalization, most people understand it to be relatively as harmful as alcohol and treat it accordingly, in pop culture and in their lives.

Also, I’m not sure that The Sarah Silverman Show is intended to show any of the characters as a positive role model.  And Montopoli realizes that Real Time is a political talk show and not a sitcom with fictional characters, doesn’t he?

I think that the push for legalization may be coming, but I don’t think we had a seminal moment in politics when Family Guy squeezed in a positive reference to marijuana between fart jokes.  If and when the American public changes their minds on marijuana, it will be because the prohibition costs far more than it’s worth, both in terms of cash and in civil liberties, and not because Harold and Kumar went to White Castle, or the Family Guy dog went to jail.