The Sierra Club membership demonstrates its recognition that immigrants are not the problem: After weeks of highly publicized warnings that anti-immigration outsiders were trying to take over the venerable Sierra Club, the club's members on Wednesday overwhelmingly supported all five candidates put forward by the group's formal nominating committee. The three candidates whose participation became the focal point of the controversy were former Gov. Richard Lamm of Colorado, a prominent critic of immigration policies; David Pimentel, a noted Cornell University entomologist; and Frank Morris, the former executive director of the Congressional Black Caucus Foundation. But the three finished at least 95,000 votes behind the winners, placing 11th, 12th and 15th in the race that had a total of 17 candidates for the five three-year terms.