I had never heard of Hare Krisha, but your question intrigued me so I looked it up. I guess you could say that answers the question right there. Even though I am in Northern California and frequent San Francisco, I never hear about this group. If there is an enclave in San Francisco, it's a quiet one. Sometimes it takes years for these types of groups to die out.
I agree that the Hare Krisha are not nearly as visible as they once were, but I do not necessarily agree that the movement is "dead."
I live in Dallas and we have a huge Krishna temple downtown. I have been a couple of times, and it was packed. In addition, they have one of the best vegan restaurants in town, Kalachandi's, which people come to by the hundreds, even if they have no other interest in the temple activities.
If you want a better answer about the viability of modern Hare Krisna's, visit their website and contact them via email. Everyone I have ever met there has been very kind and helpful and I'm sure they'd be happy to assist you.
I believe that the Hare Krishna movement is essentially dead in modern America. It was very visible for a decade or so beginning back in the mid-1960s, but it is not any longer.
For a while back in the '70s, it seemed that you could not go out anywhere without seeing Hare Krishnas chanting and asking for money and recruiting. The movement had resonance with many American youth in those days because there was still a strong anti-authority feeling among the young. This feeling was a remnant of the 1960s counterculture and the hippie movement.
Today, there is no such feeling. American youths in general do not feel the same alienation from the older generations as they once did. They do not feel the same disdain for materialism. Because of this, I would argue, the Hare Krishna movement no longer exists to any large extent in the US.
The Hare Krishna movement is still alive in America, but agressive book distribution has definately dropped off, and most members prefer to keep a lower profile. There are still large numbers who turn out for special events at their centers. And there are many small groups in all the major cities.
Go to www.Krishna.com to learn more.