Why? Obama is a public figure - perhaps THE most public figure - so he would have to prove that the statement Rush made was knowingly a libel of Obama. Rush could certainly show a lot of reasons why he sincerely believed what he said (assuming that BO was actually born in HI and can prove it in pleadings to the court), thereby killing BO's case. Further, what's the damage? Seriously, what's the cost to Obama is Rush Limbaugh says "he wasn't born in Hawaii?"
Fauxbama has no libel case.
Seriously, what’s the cost to Obama is Rush Limbaugh says “he wasn’t born in Hawaii?”
He can either cough it up, or resign himself to being a one-term, lame duck only six months into his administration.