Back in the days when a presidential candidate hired someone to write a campaign theme song, the result usually was a silly, innocuous ditty whose significance was far more historical than artistic. In our enlightened age, by contrast, a candidate is now more likely to pluck a familiar song from the public domain in order to turn on the multitudes. The result, regrettably, can be a silly, innocuous lawsuit the implications of which go well beyond elections. That brings us to one of the more intriguing political sidelights of 2008. This past August, singer-songwriter Jackson Browne sued Senator John McCain...