If Carlson represents America in that time period, how does he show that not all hope is lost for them?
i.e. How does Carlson show an America that has NOT gone awry (compared to how America has gone awry - do not need to know this)
As you have accurately stated, John Steinbeck's novel Of Mice and Men portrays the character of Carlson as a callous and heartless man whose background as a mechanic seems to be allude to his own sterile and cold character traits.
Although there are few to almost no redeeming qualities in him, we could argue that, at least, Carlson still kept one thing in common with the field hands, and it is his hatred towards Curley's bullying. This entails that Carlson still somewhat connects to the "smaller man" and wishes justice from an abusive and overpowering "big man".
This is representative of the typical American because, even though Carlson is the way he is as a person, he is still a man who has to work hard to put bread on his table. Moreover, he joins forces with Slim and the rest to create a united front against Curley. Even more interestingly, he actually threatens to hurt Curley (who represents the bigger elements at work in an unequal American society) if he dares to hurt him.
You tried to throw a scare into Slim, an’ you couldn’t make it stick. Slim throwed a scare inta you. You’re yella as a frog belly. I don’t care if you’re the best welter in the country. You come for me, an’ I’ll kick your God damn head off."
Clearly, these words are significant in that they echo the working man's basic tenet: I am working to earn a living, so don't mess with me....or else. It is a clear aim to defend what he believes he has the right to defend: His right to be left alone making the best he can out of what he has. There is no need for some social obstacle, nor a social bully to tamper with the natural order of the working man. Live and let live, or get ready for the consequences. That, if anything, is what shows that Carlson still represents an America that still sticks to its guns.
Carlson represents the modern "Mc Donalds American." He is referred to by Steinbecj as "thick-bodied" and "big stomached." As you may already know, people who are overweight (i.e. fat) tend to be rather jolly hence the term "bubbly" which refers to their circular appearance and their jolly personality. In the times of The Great Depression (as the word depression implies,) people were feeling down in the dumps and their only joy was to laugh at fat people.