How does the United States government differ from the Argentinian government?

One significant difference between the United States
government and that of the Argentinian might lie in its history.  The United States has
had a longer history of constitutional democracy than the Argentinian version.  One need
only look at the autocratic history of Peron as well as the governmental edicts such as
"the Dirty War" as an example of this.  While America's history has had many moments
where the denial of rights is a part of the narrative, there has not been overt moments
like the Argentinians.  One need only examine the "mothers of the disappeared" as a part
of this process.  Another difference between both nations' form of government might
actually show Argentina to be more progressive than the United States.  Political
parties that wish to be elected in Argentinian government must have a third of their
slates for election as women candidates.  This is vastly different than the United
States where no such stipulation exists.