Yes I do. I am both pessimistic and optimistic of grass roots movements occurring, so how much of a realist I am, I am not sure. I see grass roots with politics from where I sit with local organic farming. To me that is a grass roots movement. Unfortunate as politics is driven by trends - social and economic, I see those two mixing two heavily in that blossoming grass roots movement.
It is national, yet it is very much local. We have local organic farmers here in the San Diego area and very little farmer markets as meeting places for those. There are road side stands more than not. Most is exported of least within the state. The local nationally owned markets - Albertson's, Vons, and others do buy local, yet the definition for local is diverse and wide.
One example as a main staple are avocados. The growers are both national and international. Their product usually is not distributed as a local farmer, but as a conglomerate of growers through a distributor.
Maybe I digressed from a movement specifically being political, yet those politics are driven by the trends of social and economic. Business trends drive in my humble view politics much more than issues. Grass roots I see occurring, yet they just do not seem to become a forest. And, when they do I see more big business clearing the forests and then we wait for the seedlings to grow over too many years.