Is it true that 'Joe the Plumber' is a republican right wing plant?

First if he is a plant he needs to come out and say that he is for McCain. Beating around the bush like this isn't getting the point across. I know what he's trying to do but I'm not sure hes a plant. He looked really awkward on tv this AM not confident like someone who was trained to do so would. He took off because of something Obama said about spreading the wealth around.