While I applaud you thinking outside the box on this I am forced to disagree.
The US is not a Democracy it is a Constitutional Republic. It is set up this way to ensure that the will of the majority cannot impact the rights of
the minority. If the simple majority is allowed to make all the rules, this country would not be the place it is now. Just imagine what may have
occured immediately after 9/11... Allowing control of laws to the majority would lead to a mob mentality. Im not saying that we would have death camps
the next day, but, IMHO, things would quickly go south and many of our freedoms would slip away in the name of security, safety, etc...
Not saying that Congress is doing a good job, they stink.
EDIT- Also, many of your examples, namely allowing the majority to approve measures could have the same effects. As example, many civil rights
movements would have been squashed fairly quickly... just my 2 cents
[edit on 26-7-2008 by XTexan]