The state of realizing, after initially holding high expectations and hope that President Obama would be an effective president, that he has failed in delivering. It usually only inflicts those who voted for him in 2008 (rather than to those who did not vote for him), and did not manifest until approximately 2010 (after a substantial time in office). But it may last a lifetime.
It takes two forms: 1) those who don't think he's done enough, and 2) those who think he's done far too much.
I was excited when President Obama was elected, but after seeing him in action, I've got Obama Disappointment Syndrome. I see him as a finger pointer and a blame shifter, who only has one answer to everything - throw money at it.