Originally Posted by
scott523
I'd say the officer couldn't think of a better way to say he wasn't satisfied. Such as the photo or condition. Is a passport a valid form of ID on domestic flights? Definitely. Is it as fast/easy as checking a drivers license? No, but not impossible. Since passports are more susceptible to being damaged, be prepared for another form of ID to verify upon request.
Like what? I don't take my DL when I travel overseas because I don't drive overseas. I don't carry anything overseas unless I intend to use it (gas credit card also stays at home). I used to carry a xerox copy of my passport, but now I store it in an online vault in case of emergency.