Remember That Time The Simpsons Burned Idaho
If you watch the Simpsons TV Show, then you know that when it comes to Ralph Wiggum - he's not the sharpest crayon in the box.
So, when The Simpsons had Ralph (poorly) portray Idaho in a school project it was clear they were trying to make a dig at Idaho. To add fuel to the burn and extinguish any doubt that they really wanted to make fun of us, Ralph states 'I'm Idaho' and Skinner replies 'Of course you are'. Yep. The Simpsons thinks Idaho is the Ralph Wiggum of the United States.
Side note - Ralph is kind of shaped like a potato.