“Socialism never took root in America because the poor see themselves not as an exploited proletariat but as temporarily embarrassed millionaires.”

I’ve seen this quote attributed to Steinbeck - this direct quote. I tried to find out where, exactly, it came from, and all that I could find was that it is an inspired quote, likely from Steinbeck’s America and Americans. Can anyone tell me that this is a direct quote? Because, even though I do agree with the sentiment, it disappoints me that people so happily take quotes without their context when it suits their desires.