Yes. In the case of Barack Obama, he may be a US citizen, but is he a “natural born citizen”, which can only be confered by a US citizen mother and US citizen father? We know that Barack Obamas father was a Kenyan national. Barack Obama has self-certified in all 50 states (I presume) that he meets all the Constitutional qualifications and is indeed a “natural born citizen”. There are many questions as to the veracity of his statements, and since he has sealed his documents and refuses to release them, the questions remain.