Accepting his party's presidential nomination in the summer of 2008, Barack Obama beamed while Denver's stadium rocked with gauzy chants from adoring admirers. But looming beyond the deafening roar was a harsh reality that too few were willing to face just yet: Some "hope" is too audacious to believe, and just because a smooth talker proclaims something, doesn't make it true. Now, long after the honeymoon has ended and the national mood soured toward...