After this week's tragedy at the Holocaust Museum in D.C., the threat right wing extremism has been on everyone's mind. Now, a new book, Blood and Politics: The History of the White Naitonalist Movement from the Margins to the Mainstream, Leonard Zeskind offers a look into little-known and rarely understood hate groups in America. According to studies, there were 926 hate groups active in the country last year, with an estimated 30,000 people linked with the "white nationalist hard core." Zeskind offers a historical and sociological tour of many of these groups—from the skinheads to the Klu Klux Klan. But, according to Art Winslow in the Los Angeles Times, Zeskind proves a larger point by illustrating that these random groups are not all, in fact, separate. Writes Winslow: "Given such diversity, if Zeskind had not provided connective tissue showing significant contacts between groups and cross-pollination over time, "Blood and Politics" would seem merely a compendium of relatively fringe groups and their leaders."