Talking about Paris and Britney is not talking about healthcare and Iraq. There were 85 million potential voters who didn't vote in the last election. Obama needs to let them know what he can do for them.
Sounds like "celebrity" applies to both these men who happen to be running for president, spending millions to reach out to voters who see them every day on TV, in the papers, and staring up from magazine covers. But otherwise, totally anonymous.
I can attest to the effectiveness of Obama's message because my political involvement is a product of his candidacy. Republican mockery is not an equal response. Citizen involvement is a victory for the country.