Natural Born and Naturalized are the only two types of citizens as far as the law is concerned. There is no mythical third category of "citizen born in America but not eligible for the presidency due to foreign parents" as many here would like to believe.
You are either natural born (born in the USA) or naturalized (Arnold Schwarzenegger). That is it. Hawaiian-born Obama is natural born. He is eligible for the presidency (as the photos I linked to demonstrate).
And, yes, as President, he is a disaster. Nonetheless, he is eligible.
U.S. v. Kim Wong Ark determined the American born children of foreigners were citizens and Ankeny v. Daniels applied this ruling specifically to President Obama in affirming his eligibility.
The Constitution mentions two types of citizens:
"Citizens" as being a requirement for Senator's and Reps.
and
"Natural Born Citizen" as being a requirement for the President and Commander in Chief.
The framers made a distinction in the Constitution.
Then he's eligible to be a Senator.
"citizens" not "natural born citizens". Congratulations, you just shot a hole in your own desperate argument.