Glenn Greenwald points out why no amount of pressure, no prodding by the wise old men of Washington, not even single-digit poll numbers will make George W. Bush change his mind:

This has been the great unexamined issue of the Bush presidency -- the extent to which Bush's unwavering commitment to Middle East militarism is, as Bush himself has made clear, rooted in theological and religious convictions, not in pragmatic or geopolitical concerns. That Bush's foreign policy decision-making is grounded in absolute moral and theological convictions and therefore immune from re-examination or change is an argument I examine at length in A Tragic Legacy because it is one of the principal -- and most dangerous -- forces driving the Bush presidency.

This is a religious war for Bush, between good and evil. He answers only to a higher authority, not to the people who elected him.