Anyone can be wealthy, but then again, anyone can win the lottery. The possibility of wealth doesn't mean much. The likelihood of wealth is everything. For the most part, America has the most economic mobility of any country. In other words, you have the best chance of becoming wealthy in this country as opposed to any other. However, that still doesn't mean that your likelihood of getting rich is significantly better by living here.
The typical interpretation of the "American Dream" is quite fantastical. Going from rags to riches happens, but not that often. It's far more likely that a poor person will move to the middle class rather than a middle class person will become wealthy. Poor people almost never get rich; it's far more likely that a rich person will become poor.
Getting rich is very much a situational phenomenon, so it's hard to come up with a general rule that accurately covers this overall occurrence. What history and my personal experiences have seemed to support is that getting rich involves a combination of business skills, personal connections, and luck. The luck part most blatantly applies to people that are born with money. One of the most successful people in the modern business world, Bill Gates, was born with money. Granted, he ended up raising far more money than he started with, but nonetheless, his business plans would have probably never gone anywhere without having ready access to the capital he needed.
As a final note, Jim's remark about the left demonstrates a sad truth about American culture. We have some of the lowest taxes in the First World, and yet, the rich still want lower taxes, because that's how greedy they are. They don't care if it means harming the rest of us through not having properly funded social programs.
