And that is The Grapes of Wrath summarized, really - the voice of the people must be heard and cannot be silenced by violence or oppression. As the book itself asks:
How can you frighten a man whose hunger is not only in his own cramped stomach but in the wretched bellies of his children? You can't scare him – he has known a fear beyond every other.*This sentence brought to you by the cranky old lady who wonders why kids these days want to listen to all that loud noise.