Election Day 2008 must have been filled with rueful paradoxes for the sitting president. Iraq -- the issue that dominated George W. Bush's presidency for 5 1/2 bitter, controversial years -- is on the verge of a miraculous peace. And yet this accomplishment did little to revive Bush's political standing -- or to prevent his party from relegating him to a silent role. The achievement is historic. In 2006, Iraq had descended into a sectarian killing spree that seemed likely to stop only when the supply of victims was exhausted. Showing Truman-like stubbornness, Bush pushed to escalate a war that...