Presidential Independence

Why does the President have to be the "head of the Party"? It's certainly not a Constitutional requirement. Once elected, our Presidents should act independently of any political party and act on behalf of the US citizens and their own principles, that hopefully they clearly defined before their election to office.

President Bush would catch holy hell, if he took this position for the remainder of his 2nd term, in light of the 2006 midterms. However, the 2008 Presidential candidates of all parties should change the paradigm and turn down their party's leadership role. It would free them to make better decisions and be less political in their role as President of the United States of America.