Twenty years ago, NBC's "Today" devoted three days of interviews to the insufferable Kitty Kelley, who unspooled baseless allegations against Nancy Reagan, like her supposed love affair with Frank Sinatra. That kind of tabloid bilge belched back up the garbage disposal on Sept. 16, when "Today" promoted the new Palin-bashing book "The Rogue," by leftist author Joe McGinniss. NBC doesn't have an evidence standard when its conservatives are being gored. With liberals, it's a different story. NBC didn't give a second to McGinniss after liberals roundly condemned him in 1993 for his Ted Kennedy book "The Last Brother." In 1996,...