Jeff Greenfield considers the perennially predicted -- and this year, superficially likely -- brokered convention and concludes that it won't happen. Why? Because the Democratic Party hasn't had brokers for 40 years. This year, it's every superdelegate for themselves, which means that though it may prove a contested convention, it's unlikely to be brokered. The smoke filled room doesn't fit 900 people. And when it's a smoke-filled arena, there are too many cameras for a backroom deal.