By Rex Nutting, MarketWatch
WASHINGTON (MarketWatch) -- In his frivolous Paris and Britney ad, Sen. John McCain has asked the right question: Is Barack Obama ready to lead this country?
Since last January, Sen. Obama's fitness for the presidency has been the only question that matters in American politics. The pollsters and pundits agree that if Obama can show the voters that he's up to the job, he'll win. If not, he won't.
But that begs another question: Is McCain fit to lead America?
That question hasn't been asked, nor has it been answered.