The shooting and subsequent rioting in Ferguson, Missouri, like the killing of Trayvon Martin or countless incidents before it, will not produce a "national conversation" on race. If Americans can elect a black man president without ever having such a conversation -- we've done so twice -- we're not about to have one over the umpteenth violent death of a young lower-class black male.
Regardless, a conversation -- on any topic -- requires shared predicates and vocabulary. You can't have a conversation about global warming with interlocutors who contend that thousands of scientists around the globe, speaking different languages and working for different governments and unaffiliated institutions, are co-conspirators in a vast enterprise for no apparent gain. You can't have a conversation about government's impact on the economy with people who believe that the federal government spent $800 billion -- dropping it from helicopters or otherwise -- without creating a single job. And you can't have a conversation about race with people who believe that claims of racism are inherently bogus, or who have convinced themselves that Democrats, the president very much included, intentionally encourage black dependence on government for political reasons. The common denominator among those views is a crude form of denial -- a refusal to acknowledge the legitimacy of experience outside the universe of talk-radio claptrap.