SAN FRANCISCO -- Sierra Club leaders have beaten back an effort by anti-immigration forces to gain control of the nation's largest and most influential environmental group. In elections for the Sierra Club's 15-member board of directors, candidates picked by the leadership won all five open seats in a landslide, according to vote tallies released Wednesday, several hours after voting closed. The bitterly contested election had been conducted by mail and online since March 1. "It's a stunning rejection of the anti-immigration forces," said Adam Werbach, the club's president from 1996 to 1998. "I think people realized that there's no role...