LOS ANGELES - As a Pakistani, Hamid Khan stood out among the Hispanics he marched alongside at a recent immigration law protest. When he told one demonstrator where he was from, the man responded: "'Then what are you doing here?'" Khan was surprised. "I said 'Look, there are non-Latino groups who are also suffering under these laws,'" said Khan, 49, a commercial pilot and director of an advocacy group called the South Asian Network. Hispanics, the nation's largest immigrant group, are leading the movement to demand a path to citizenship for illegal immigrants and defeat legislation that would criminalize them....