Alice, George W Bush once remarked that "Africa is a very big country," but I don't for one minute believe that he really didn't realize Africa is a continent and includes such countries as Egypt, Ethiopia, Kenya, South Africa, and Zimbabwe.    Just as, when Joe Biden quipped that President FDR, back in 1929, after the stock market crash, got on TV to talk to the American people ... , I have no doubt he knows that FDR wasn't President in 1929 and that he addressed the nation on radio (since TV hadn't been developed for consumer use while he was in office).
Sometimes the mouth gets ahead of the brain and people say dumb things which they KNOW are wrong, if they reflect for a moment.    No need to make a Federal case over it.

Palin may well have been confused about what many of the African countries ARE. Maybe she thought there was a country called "Africa" within the continent, sort of like we in the US refer to our part of "North America" as "America" and within the US we have both a "Virginia" and a "West Virginia."   Who knows?   But she does have a high school diploma, in addition to her bachelor's, and most kids learn basic geography in grade school.