I don’t know if “refudiate” is a gaffe or not. It was taken to be so by the press, but Palin might have coined it on purpose, as kind of a Bushism, e.g., misunderestimate. What did Palin say about it?
"Make no mistake; I refudiate their refudiation."
Here are some gaffes.
http://deathby1000papercuts.com/2010/04/barack-obama-quotes-ten-famous-obama-gaffes/
http://www.youtube.com/watch?v=p9hZpJp7U3Y
The breathalyzer episode is painful to watch .
I thought ‘misunderestimate’ was a SNL parody of a Bushism, sort of like accusing Sarah Palin of saying she could see Russia from her house. I’m not sure that Bush ever said that, but I could be wrong.