What is Obamao hiding, and why is he hiding it?
His Past. His life history.
The reason he's hiding it all is that it will:
1) show he is Constitutionally not eligible to be POTUS and Commander in Chief..thus calling into question as legal ANYTHING he signed into law, or his SCOTUS pick(s), etc.
or
2) show Sr. was not his legal father at birth...thus calling into question the altered government document posted proudly on his campaign web site...not to mention that it would expose his public life as a lie.