I could really relate to this discussion of the "radical imagination" because I experienced it in the 1960s and early 70s. It was such an exciting time. We questioned everything, and felt that everything was possible. By contrast this period we are now living seems so false, so dead, so pitiful. (Whenever I see small children in my neighborhood, I worry for their future.) This wonderful experience of my youth has haunted me ever since, and I always yearn for this kind of experience to return to the US in the form of a vibrant subculture that can challenge the domination imposed on all of us by the neoliberal ruling class. It's not clear to me how much this sort of imagining is happening now. There are definitely signs of hope that are inspired by people like Bradley Manning, Julian Assange, and Edward Snowden. But we need far more people to question and to act, now more than ever before.
Because the "radical imagination" and our memory of things past are such major threats to the ruling establishment, they have made an enormous effort to kill them through their control of major indoctrination agencies--education, media, and entertainment. This is so because as stated by Professor Haiven, "the way we remember the past always shapes what we think is possible in the future". The capitalist ruling class doesn't want us to believe that our future can be anything other than this neoliberal nightmare.
I highly recommend listening to this interview.
P.S. Important mention is made of the book entitled May '68 and Its Afterlives by Kristin Ross.