Barack Obama has purchased a half-hour of primetime television on CBS and NBC, sources confirmed Thursday.The Obama campaign is producing a nationwide pitch to voters that will air on at least two broadcast networks. The ad will run Wednesday, October 29, at 8 p.m. -- less than a week before the November 4 general election....Such a move is not without precedent in modern presidential politics, however -- Ross Perot did a similar purchase in 1992.
