Dana Milbank, a Washington Post columnist who has written a new book on Beck, has been tracking the case of Byron Williams, a bank robber on parole who injured two California Highway Patrol officers in a July shootout. Williams was out to start a revolution, his mother said, because “Congress was railroading through all these left-wing agenda items.” But instead of picking Congress as his target, Williams was gunning for progressives closer to home, at the Tides Foundation and A.C.L.U. in San Francisco. The Tides Foundation? It’s an obscure nonprofit whose agenda includes education and AIDS prevention. But it’s not obscure to Beck fans, who heard him single it out for vilification 29 times in the 18 months before Williams grabbed his gun.