Misunderestimate
One of the first words George W. Bush made up, this one following the disputed presidential election. No, the one in 2000. Broken down to its basic elements, the word makes sense when discussing Mr. Bush. Underestimate: Guess a value too low. Mis–: Bad, erroneous or lack of.
Over the next eight years, it became painfully obvious that Americans had erroneously not guessed a value low enough for Mr. Bush. It’s use is allowed in references to the Bush Administration.