Meanwhile, Obama has engaged in his first public spat with independent presidential candidate Ralph Nader following Nader’s criticism of his campaign. In an interview with the Rocky Mountain News, Nader said Obama is trying to appease white voters while ignoring African Americans.

Ralph Nader: “There’s only one thing different about Barack Obama when it comes to being a Democratic presidential candidate: he’s half African American. Whether that will make any difference, I don’t know. I haven’t heard him have a strong crackdown on economic exploitation in the ghettos — payday loans, predatory lending, asbestos, lead. You know, what’s keeping him from doing that? Is it because he wants to talk white? He doesn’t want to appear like Jesse Jackson? We’ll see all that play out in the next few months and if he gets elected afterwards.”

On Wednesday, Obama dismissed Nader’s criticism.

Sen. Barack Obama: “First of all, what’s clear is Ralph Nader hasn’t been paying attention to my speeches, because all the issues that he talked about, whether it’s predatory lending or the housing foreclosure crisis or what have you, are issues that the traveling press can tell you I’ve devoted multiple speeches, town hall meetings to throughout this campaign. Ralph Nader is trying to get attention. He has become a perennial political candidate. I think it’s a shame, because if you look at his legacy in terms of consumer protections, it’s an extraordinary one. But at this point, he’s somebody who’s trying to get attention and whose campaign hasn’t gotten any traction.”