¡Viva la causa!<P> ¡Viva César Chávez! <P> Up and down the San Joaquin Valley of California, and across the country, people chanted these words. Cesar Chavez, a migrant worker himself, was helping Mexican Americans work together for better wages, for better working conditions, for better lives. <P> No one thought they could win against the rich and powerful growers. But Cesar was out to prove them wrong -- and that he did.