The bullet trains that would someday streak through California at 220 mph are, in the vision of their most ardent supporters, more than just a transportation system. They are also a means to alter the state's social, residential and economic fabric.
But those broader ambitions are triggering an increasingly strident ideological backlash to the massive project.
The fast trains connecting Los Angeles and San Francisco would create new communities of high-density apartments and small homes around stations, reducing the suburbanization of California, rail advocates say. That new lifestyle would mean fewer cars and less gasoline consumption, lowering California's contribution to global warming.