Environmental groups, lured by the prospect of more than $4 billion for public-transit projects, are backing away from opposing the massive transportation bond on the November ballot. The environmentalists also are daunted by the nearly $7 million in campaign funds amassed by the bond's supporters. Over the weekend, the 75-delegate board of the Sierra Club of California decided against opposing the $19.95 billion bond package, which includes the money for public transit and $14 billion for road construction, plus other projects. Bill Allayaud, the group's legislative director, said Northern California members pushed to fight the bond, while many Southern California...