The two pieces of rhetoric that you've chosen seem good, but to take your argument even further maybe you could find some complimenting rhetoric where American Citizens, the ones affected by the economy, talk about how they feel about the changes and how those changes have affected them.
I think the connotation of balanced budget is a great way to link the two speeches. The evolution of theory to accomplish this task articulated by two of the most respected presidents of their parties should provide great contrast. Another place where the shift may be obvious would be if you could find debates between Carter and Reagan.
I like your analysis but I think you can include a little about analysis of Burke with the vocabulary words in the book to help.