If you are looking at the U.S. for architecture of democracy then u are lookin in the wrong place. All of our government buildings, monuments and memorials are neoclassical with a doric emphasis. The values portrayed are Masculinity, Strength, Brotherhood, and are better associated with Capitalism than with Democracy. I would suggest comparing whatever you think democratic architecture to be, to architecture that is profoundly undemocratic i.e. the works of Albert Spear, or Soviet era design. I think then u will notice there are more similarities than differences between them. Another good theme would be to analyze freedom of expression in architecture.

hope i helped some, and good luck!