Why exactly did you have questions about Obama's birthplace? Or if you didn't personally, what was your understanding of why other people had questions? Did they give you reasons? Or did you follow your own reasoning as to why, and if so, what was that reasoning?
The problem was not a lack of qualification, it was that he never proved his qualification and there was reasonable doubt. The only reason he released his birth certificate or whatever it was is that Sheriff Joe vowed that he would not be elected to a second term without it, and whatever you think of Sheriff Joe, he is not a man to be ignored.
I'm not clear on where this "reasonable doubt" came from. I've never seen this happen with any other president. What caused so many people, including public figures, to doubt his citizenship status?