Any politician is gonna have 'splainin' to do over one thing or another. The question then becomes, "do I believe the explanation".
I have to say for myself that an explanation without admission of a mistake seems like pandering and justification, every single time. Admissions of mistakes made - and better yet, apologies for them - goes a long way with me. But even then, I'm looking for a sign of authenticity.
I buy Perry's admission, but I also can't shake the sense that he's an awful lot like George W. Bush. Eerily so at times.