Barack Obama, a month ago: Democratic Party savior. Cool, smart, black, great personal story. Barack Obama, this week: All flash, no substance. Fast and loose with facts, Hillary will pummel him. After a Las Vegas health care forum last week, Obama was deemed a disappointment by a national magazine writer, and the theme multiplied: Los Angeles Times, The Politico, the Associated Press, CNN. The chattering herd loves a narrative, and this year, just as in past presidential years, the media are moving like a pack, hunting for their beloved conventional wisdom. The names are unfamiliar to most Americans - Klein,...