The article is written by Thomas L. Friedman of the New York Times, a highly liberalized news outlet. The article was written one day after the Obama inauguration, i.e., a very jovial time for a many Americans. The audience it was directed towards is generally most Americans but especially Americans who are affected by his new presence.
The basic argument Friedman is trying to make is that he is hoping that Obama is more than advertised. He states that he hopes that he is a radical in the since of his idealism and forthcoming actions. When the country, like it is now, is facing such dire needs, Friedman thinks that we need Obama to not just take ease and conservative measures at fixing our problems, but really swing for the fences and basically overachieve.
I personally believe that Obama is one of the better things that has ever happened to the U.S. His election has helped unify the people, bringing in a large part of the population to become more patriotic, a section of the population that generally has never cared much about politics and govt. However, I don't think that political rookies quite understand all that is really going on or that is on the table. Obama's laundry list of messes to clean up from the last administration is way more than one page and to think that he is going to be able to clean them all up in 4-8 years is a bit ridiculous. Bush has set the USA back 40-50 years and people need to recognize that. Even Superman and Batman needed help.