Drought
For the people in this community, drought represents absolute desperation. Not only do they not have food to eat, they don't have work to sustain them. This drought signals that they will be at the mercy of their employers, because their work is conditional on the seasons of course. Then again, they are skilled in this kind of labor; there aren't enough jobs in town to keep them all employed. The drought signifies the intense battle for survival that defines communities of laborers.
Life among migrant workers
There is a serious political issue raised by Steinbeck who sees that (not of their own fault) the migrant workers can afford to live very cheaply on minimal incomes, whereas the Americans live with a different economy where their dollar doesn't go as far. Plus, they aren't migrants; they can't just get up and leave, because their families are stationed in the States, not in Mexico where cost of living is lower. The problem as Steinbeck sees it is not that migrant workers are "stealing jobs," but that employers are short-changing their employees.
Unemployment relief
The relief that should apply to the workers often doesn't, because there are clauses in the legislation that disqualify workers who earn money by seasonal work. Steinbeck sees this as evidence that the real problem is not situational, but systemic. The system is not only not prepared to help their own laborers, but they seem prepared specifically not to help. This signals to Steinbeck that the law itself is bent to help some people, but not the poor.
Infant mortality
Steinbeck's research takes him to this symbolic realization. The mothers in these camps cannot afford to eat, and because they aren't getting enough necessary nutrients, their children are dying. This symbol is existentially significant to Steinbeck and to the reader, because these communities are being told through neglect that their own survival is not worth assisting. They are being allowed to die while the nation watches.
The need for reform
Through motif, the reader encounters a litany of problems that show the need for reform. This isn't a political battle between left and right, it is a simple question. The people who harvest the food we eat; do they deserve to live? Do their babies deserve a chance to live life, or is it alright that they die in fields whenever a drought comes? The essays are obvious. The only other solution might be to prevent droughts forever, but since that's out of human control, he says it's time to legislate more equitably so that these people can live.
