To what extent is Steinbeck's Of Mice And Men a novel of protest?

Of Mice and Men is a novel of protest. Steinbeck portrays the plight of the working person in stark terms. George says at the beginning of the novel:

“Guys like us, that work on ranches, are the loneliest guys in the world. They got no fambly. They don’t belong no place. They come to a ranch an’ work up a stake and then they go into town and blow their stake, and the first thing you know they’re poundin’ their tail on some other ranch. They ain’t got nothing to look ahead to" (page numbers vary by edition).

George and Lennie's lifestyle illustrates the plight of the working class. Though they work hard, they have nothing to show for their work. Instead, they travel from place to place, and, though they want their own farm, it's doubtful that they will be able to accumulate enough money to purchase their own land.

The novel is also a form of protest against other forms of prejudice and a form of advocacy for the dispossessed. For example, Lennie is constantly misunderstood because he is developmentally disabled, and Candy, the old ranch hand, is treated with such little regard that Carlson, another ranch hand, wants Candy to shoot his beloved old dog. Candy is of little use on the ranch because his arm has been injured, and Steinbeck's sympathetic portrait of him is a means of protesting the poor treatment of the dispossessed and weak in our society. In addition to being a novel of protest, Of Mice and Men is also of literary value because it is eloquently written and speaks about timeless themes such as friendship, fairness, and love.