Since then, the California High-Speed Rail Authority has been unable to attract outside investors and doesn’t have even 40 percent of the money it needs to complete the initial 300-mile, $31 billion segment — much less the $68 billion needed to build a rail line linking San Francisco and downtown Los Angeles. This has led bullet-train advocates, starting with Robert Cruickshank of the California High Speed Rail Blog, to repeatedly urge Congress and the Obama administration to provide more federal dollars. In planning documents from three years ago, state officials said they were hoping on $42 billion in federal help.