the best way i can explain it, is when i looked at 2004 it seemed fairly straight forward that Congress was the primary authorizing agency. The next one i looked at, Congress was not seen at all and the Iraq war picture was very large. I was thinking of how people would react since most see this when they do their taxes, its with the tax forms.
In the first picture- people would most likely pin it on Congress
In the second people would react against the iraq war (bush/republicans)
it really was a general impression to the two charts, and thats the best i can explain. if it means nothing, well not my first post like that