Baum certainly saw the results of the frightful depression which had closed down up on the nation in 1893. Moreover, he took part in the pivotal election of 1896, marching in "torch-light parades for William Jennings Bryan". Martin Gardiner notes besides, that he "consistently voted as a democrat...and his sympathies seem always to have been on the side of the laboring classes." No one who marched in even a few such parades could have been unaffected by Bryan's campaign. Putting all the farmers' hopes in a basket labeled "free coinage of silver," Bryan's platform rested mainly on the issue of adding silver to the nation's gold standard. Though he lost, he did at least bring the plight of the little man into national focus
Not understanding the magic of the Silver Shoes, Dorothy walks the mundane -- and dangerous -- Yellow Brick Road. The first person she meets is a Scarecrow. After escaping from his wooden perch, the Scarecrow displays a terrible sense of inferiority and self doubt, for he has determined that he needs real brains to replace the common straw in his head. William Allen White wrote an article in 1896 entitled "What's the Matter With Kansas?". In it he accused Kansas farmers of ignorance, irrationality and general muddle-headedness. What's wrong with Kansas are the people, said Mr. White. Baum's character seems to have read White's angry characterization. But Baum never takes White seriously and so the Scarecrow soon emerges as innately a very shrewd and very capable individual.
In any case, this possible parable is an interesting read. The interpretation lends insight into some of the political happening taking place during the late 1800s and early 1900s. Others(PDF) have also given similar accounts that mirror Littlefield's interpretation.
Other inks of interest:
The Wizard of Oz: A Parable on Populism