Film plays an important role in the American political system, and forms an important branch of the mass media. I analyze the political contributions of a sample of 996 top film actors, directors, producers, and writers, correlating them with demographic, family, and career success variables. I find that contributions flow overwhelmingly to left-of-center parties and organizations. I theorize about the causes of this bias, and argue empirically that, while demographic variables are not completely irrelevant, Hollywood liberalism is primarily a function of high, publicly visible incomes, and family connections. Neither religion nor birthplace effects seem to affect political activity in the film business.