If he was indeed born in Hawaii, then the first clause of the 14th amendment makes him a natural born citizen, his father notwithstanding.
From all the many lawsuits filed with Jumbo Mumbo legal "language", I feel this is the most compelling and logical to push forward:
A more important lawsuit, however, may be the New Jersey case filed by Leo C. Donofrio. See http://www.blogtext.org/naturalborncitizen/ Donofrio is presently seeking emergency stay relief in the US Supreme Court, and what's intriguing about his action is a new legal theory not asserted (as yet) in any of the earlier cases. Donofrio argues that the "birth certificate" and "Indonesia" issues are irrelevant to Obama's eligibility to serve as President. Donofrio points out that Obama spokesmen have admitted (at least on websites) that his father was a Kenyan native at the time of Obama's birth, and was thereby a British subject (Kenya, at the time, was a British colony). Obama spokesmen acknowledge (on websites) that British law governed the status of Obama Sr.'s children, but the spokesmen also assert that Obama held dual Kenya/US citizenship at birth, and his Kenyan citizenship expired on August 4, 1981. The Obama assertion is that he was in fact born in Hawaii, and that he has never renounced the US citizenship status that arises as a result of his Hawaiian birth.
Donofrio argues that these facts admitted by Obama spokesmen establish WITHOUT MORE that Obama is not eligible for the presidency. Donofrio looks to the full clause in Article 2. Section 1. of the Constitution, which provides:
"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."
Donofrio asserts that the words ". . . or a Citizen of the United States, at the time of the Adoption of this Constitution . . ." have been overlooked in earlier lawsuits about Obama's eligibility, and that these words provide the key to a proper understanding of the eligibility issue. The Donofrio argument goes to original intent of the framers as expressed through these words-- he points out that most, if not all, of the framers of the Constitution were, at birth, born as British subjects. So the Donofrio "original intent" argument goes like this:
The chosen wording of the framers makes clear that they had drawn a distinction between themselves-- persons born subject to British jurisdiction-- and "natural born citizens" who would NOT be born subject to British jurisdiction or any other jurisdiction other than the United States. The framers grandfathered themselves into the Constitution as being eligible to be President, but the grandfather clause ONLY applies to any person who was a "Citizen . . . at the time of the Adoption of this Constitution." Obama (obviously) was not a Citizen at the time of the Adoption of the Constitution, so he is not subject to the grandfather clause.
Here's where the Donofrio argument becomes quite interesting. The framers recognized that EVEN THEY were not "natural born citizens." That's why they included a grandfather clause to allow any of them to become President. The framers did not want citizens with divided loyalty to become President in the future-- particularly citizens with loyalty to the hated British Empire. Donofrio argues that the word "born" constitutes proof positive that the framers intended that status as a "citizen" must be present at birth, since if this was not the intent there would have been no need for the grandfather clause. Dual citizenship at time of birth (British/US) was allowed for the framers themselves under the grandfather clause, but for no one else. Hence, argues Donofrio, Obama is not a natural born citizen, and even if he produces an original birth certificate proving he was born in Hawaii it will not change the fact that he was a British citizen at birth.