According to John Dickerson, Richardson's first big Meet the Press appearance went poorly:
During the course of Bill Richardson's Meet the Press appearance Sunday, the New Mexico governor was on the defensive. Permanently. He tried to explain away his state's low rankings on high-school dropout rates, poverty, and crime during his tenure, his bold statements as energy secretary that turned out not to be true, his 72-hour change of mind on the immigration bill, his stance on guns, the stock he once owned in an oil company, his brief support of Alberto Gonzales, his résumé padding on his baseball career, and the story he tells on the stump about a dead soldier whose mother has asked him to stop telling it. Richardson is a world-famous hostage negotiator, so it was poignant to watch him fail to rescue himself from his own hostage crisis. By the end of the hour, he wasn't answering questions so much as swatting at them. "I'm not perfect," he said.[...]
Richardson's many parries and contradictions might have been the work of a candidate who recognizes the world's complexity, but they weren't. He seemed not too thoughtful, but too little prepared. When he tried to explain the contradictions, like his shift on the immigration bill from supporting it to opposing it, his responses were meandering. Sometimes, he contradicted himself within just a few breaths. After explaining why he changed positions on the assault-weapons ban, he broadly asserted, "I don't change my positions." And on one of his core pitch-points—his diplomatic sixth sense for the world and the Middle East in particular—he had to admit that on Iraq, the blockbuster of the day, his skill failed him.
This is, I think, what accounts for the gap between Richardson's appeal (resume, Hispanic, Western, etc) and his support. The man is, somehow, less than the sum of his parts. His diplomatic abilities don't translate into vision or obviously superior judgment. His decades in politics hasn't resulted in historic accomplishments or inspiring crusades. His demographic advantages don't seem to amount to anything at all. His famed charisma never leaves him seeming all that magnetic. That's not to say he won't break out: His ads are good, and he does have a certain gravitas. But something needs to gel that, as of yet, hasn't.
