Check out Elmer Kelton's The Time It Never Rained after. I'd put him a slight notch below Steinbeck but it's very similar and similarly Based:

Still, whenever a man got to feeling sorry for himself in this part of the country he had only to look to Mexico to see someone in worse condition. Drouth had become a crippling plague down there—starving the fields, starving the livestock, starving the people. The migration of Mexican wetbacks swelled steadily. More and more of them stopped by the ranch, hats in hand, to ask for a job or for something to eat. Desperation lay dark in hungry eyes. More often than not, the hombres wore ragged clothes which no longer fit them. Sometimes their trousers were tied with a length of cord to keep them from falling. Charlie would watch a Mexican hungrily eat raw lard or bacon grease straight out of a can to satisfy some awful craving, and he would feel his stomach turn over.

Occasionally he came across a wetback far out in the pasture, heading north afoot. Often they scurried for cover, fearing he might be a border patrolman. Once an old Mexican walked to him with his trembling hands in the air, expecting Charlie to clamp steel cuffs on him and take him to jail. Instead, Charlie took him to the house and filled his belly, then pointed him north, into the raw wind. There was more work to the north, and fewer chotas.

When his back ached from lifting feed sacks, Charlie was sorely tempted to hire one of these men for however long he might be able to keep him. It was not the law which stopped him; Charlie shared the Mexican’s dim view of hard and fast boundary lines. He considered the law to have been passed in ignorance by people a thousand miles away who would not accept the jobs themselves and knew no one who would. The same people who cried to keep foreign workers out were happy to bring foreign wool in so they could buy it cheaper. That way they hanged the rancher on two scaffolds at the same time.