Tom H: “endorsing the O goes against EVERYTHING that I ever understood WFB to represent – SUBSTANCE OVER STYLE. … How about an analysis of what would Bill [Buckley] do?”

“Buckley himself later explained his support for Nixon in the language of a pragmatic ideologue. “I’d be for the most right, viable candidate who could win,” Buckley told the Miami News in 1967.” [EJ Dionne, Why Americans Hate Politics, p. 192]

Obama is not the rightmost viable candidate. McCain is. There’s your answer.