Based on what? He doesn't meet the "subject to the jurisdiction" requirement defined by Judiciary Committee Chairman Trumbull in the Congressional Globe (Record):
"The provision is, that ‘all persons born in the United States, and subject to the jurisdiction thereof, are citizens.’ That means ‘subject to the complete jurisdiction thereof.’ What do we mean by ‘complete jurisdiction thereof?’ Not owing allegiance to anybody else. That is what it means."Obama was born a Brit, thereby owing allegiance to a foreign power at birth.
The DNC has already publicly admitted that British Nationality Act of 1948 governed Obama's status at birth.
US Law overrides foreign law within US Jurisdiction. It doesn't matter what the British Nationality act says unless one happens to be in Britain.