What is so called white liberal guilt and how does it play into this year's election choices?

Is this notion perhaps overemphasized? It is somewhat counterintuitive that white people riding horses in Montana would feel guilty about anything. Therefore, is it less a guilt thing and more a novelty thing since they have never seen a black person, let alone one running for president? Is Obama more of a novelty phenomenon or are there really white people out there who want to be "punished" by being taxed to death? Or is it a gambling thing....ie. lets elect someone with no experience and just see how he does(the ultimate risk taking?)