He can create money out of thin air

In The Christian Almanac, George Grant and Greg Wilbur take the position that the movie version takes Baum's original intent and turns it on it's head. Unfortunately, I don't have the book at my disposal at the moment, so any interested may want to check it out. Nonetheless, this BBC article is a good introduction to the question of whether the Wizard of Oz was intended to be a political allegory:

http://news.bbc.co.uk/2/hi/uk_news/magazine/7933175.stm