That would make Obama a citizen, not necessarily a natural-born citizen which is the requirement for being POTUS.
US Constitution – Article II, Section I, Clause V:
“No person except a natural born citizen, or a citizen of the United States at the time of the adoption of this Constitution, shall be eligible to the office of President; neither shall any person be eligible to that office who shall not have attained to the age of thirty five years, and been fourteen Years a resident within the United States.”
Just because you’re a citizen, doesn’t mean you’re a natural born citizen and meet the qualifications to be Commander-in-Chief of the Armies of America.
Now, if you want to address the fact that we do not have a fully codified legal definition of “natural born citizen,” that’s a whole different matter.