In this image taken from video and provided by Worldwide Pants, Inc., Republican presidential candidate Rick Perry presents the "Top Ten Rick Perry Excuses," on the set of the Late Show with David Letterman. AP hide caption toggle caption AP The Two-Way VIDEO: Gov. Perry's 'Top 10 Excuses' November 11, 2011 On David Letterman, the Texas governor had some fun at his own expense. Excuse No. 10: ""There were three reasons why I messed up last night: 1) The nerves 2) The headache and 3) Um...Uh...Oops."