No politician with a bit of sense would go on the gameshow. The whole premise is stupid anyway, knowledge about specific facts is not an indicator of intelligence; these kids just have the facts fresher in their minds. I'm sure there's many things I learned in 5th grade that I don't remember now.
Any politician could have their chances ruined by gaining a reputation as "stupider than a 5th grader" just by not knowing some random fact. People are generally stupid, and would actually believe that retarded gameshow is a valid indicator of intelligence.