Answer:
The American dream was a nice concept, but rarely achievable by most people. I'll use the cogs and clods example for this. If every person had a perfect life, lots of money, and a nice house, money wouldn't have any value anymore. So, for a community to thrive, there needs to be cogs (Rich/successful people), and clods (Less money, less successful). In short, it was and is achieveable, but only to the priveledged few.