If you were watching cable yesterday, you'd have thought that the capital had been moved to Little Rock. The media can't resist a gathering of presidents, and never could resist a story line involving Bill Clinton (remember his hospital-bed advice to John Kerry?). Especially when his wife (who's also making the TV rounds, including Larry King and Greta Van Susteren) may run for his old job. But I don't remember anything like all this live coverage when Bush 41 opened his library, do you? And the ex-prez got an hour with Peter Jennings on "PrimeTime" last night. (Fox seemed to...