William Cronon is a great environmental historian and writer (and a professor at the University of Wisconsin). In fact, he is among my very favorite non-fiction writers regardless of field. In today's New York Times (here), he has a wonderful op-ed about Wisconsin's history of progressive government, the shift in party domination from Republicans to Democrats in the wake of Senator Joseph McCarthy's lunacy, and what current Governor Scott Walker has in common with Senator McCarthy.
For those who enjoy reading history, I recommend most highly two of Cronon's wonderful books: Changes in the Land: Indians, Colonists, and the Ecology of New England (Hill and Wang 2003) and Nature's Metropolis: Chicago and the Great West (W.W. Norton 1992).
UPDATE: Apparently, Cronon has now become a target of Republican leaders in the State of Wisconsin, who have filed a claim to obtain all of his e-mails referencing various political issues since the start of this year under Wisconsin's open records law (see here). Not only is this a deplorable act and an abuse of the state's open records law, it is a McCarthy-style tactic that confirms the associations Cronon drew in his New York Times op-ed.