Courts do not recognized "partial" citizenship nor do they acknowledged "defective" 14th Amendment citizenship. Either Obama is a natural born citizen or is an alien.
There is no "hybrid citizen" in that a person who is born in the United States is a "citizen" but not a "natural born citizen." In other words, stating that Obama is an United States citizen but not a natural born citizen is similar to being "partially pregnant" either he is a natural born citizen or not.
If he is not a natural born citizen because of misguided notion that he was not born under the 14th Amendment's "subject to the jurisdiction" of the United States phraseology due to the status of his alien father then he must be an alien.
However, numerous courts have held that native born children of alien parents come within the 14th Amendment citizenship clause. Podea v. Marshall, 83 F. Supp. 216, 219-220(ED NY 1949) ("It is a long recognized and well established principle that plaintiff acquired American citizenship upon his birth on September 21, 1912, at Youngstown, Ohio, even though his parents were immigrant aliens. Fourteenth Amendment, Section 1" ;Benny v. O'Brien 32 Atl 696, 697(New Jersey 1895)("Two facts must concur: the person must be born here, and he must be subject to the Jurisdiction of the United States according to the fourteenth amendment, which means, according to the civil rights act, that the person born here is not subject to any foreign power. Allan Benny, whose parents were 'domiciled here at the time of his birth, is subject to the jurisdiction of the United States, and is not subject to any foreign power."; Kwock Jan Fat v. White, 253 US 454, 457 (1920)("It is not disputed that if petitioner is the son of Kwock Tuck Lee and his wife, Tom Ying Shee, he was born to them when they were permanently domiciled in the United States, is a citizen thereof, and is entitled to admission to the country. United States v. Wong Kim Ark, 169 U.S. 649. But while it is conceded that he is certainly the same person who, upon full investigation was found, in March, 1915, by the then Commissioner of Immigration, to be a NATURAL BORN AMERICAN CITIZEN")(emphasis added); Mustata v. US Dept. of Justice, 179 F. 3d 1017, 1019 (6th Cir. 1999)("Petitioners Marian and Lenuta Mustata are citizens of Romania. At the time of their petition, they resided in Michigan with their two minor children, who are NATURAL BORN CITIZENS of the United States.")(emphasis added)
As such, there has not been one decision by United States courts that they have held that a native born child of an alien father or alien parents was not "subject to the jurisdiction thereof" under the 14th Amendment and thus was not a United States citizen.