Does congress represent a unitary or confederate feature of the goverment?

Answer 1

Confederate
http://en.wikipedia.org/wiki/Confederate_States_of_America

Although, unitary could be argued based on the belief in one God.

Answer 2

Unitary, but only as a result of the Supremacy Clause (Article VI).

Under a Confederate model, most Congressional actions would be advisory (like the European Union model) rather than preemptively mandatory. So, a Congress of the same structure could still exist, but would have a different role given the relative difference in power.