So, the U.S. passed a law that stated that Chinese people could never become U.S. citizens (we are an open-minded lot, aren't we). This guy complained, stating that since he was born in the United States and was not born to a foreign diplomat, he was a U.S. citizen under the Citizenship Clause of the 14th Amendment which states that anyone born or naturalized in the U.S. is a United States citizen.
The Supreme Court ruled 6-2 that, in fact, the Chinese kid was a U.S. citizen, having been born in the U.S. to two foreign parents, neither of whom was a foreign diplomat at the time of his birth. (There is some repeated reference in the summary to the fact that the parents were running a business, not sure why that matters, if at all.)
Obama was born to one U.S. citizen parent and one foreign parent. He was born in the United States. No evidence that either parent was a foreign diplomat at the time, so, ender Wok Kim Ark, Obama is a U.S. citizen for 14th Amendment purposes. No act of Congress can take that away.
Now, the other argument made is that Obama is not a "natural born citizen" -- I don't see any validity at all to this argument. A natural born citizen, in the strictest sense, is a person who is not a naturalized citizen. For example, Mitt Romney's dad was born in MEXICO -- I think a pretty solid argument can be made that he was a U.S. citizen, but NOT a "natural born citizen." He moved to the U.S. he was not born here
Schneider v. Rusk, 377 U.S. 163 (1964): The Court voided a statute that provided that a naturalized citizen should lose his United States citizenship if, following naturalization, he resided continuously for three years in his former homeland.
We start from the premise that the rights of citizenship of the native-born and of the naturalized person are of the same dignity and are coextensive. The only difference drawn by the Constitution is that only the 'natural born' citizen is eligible to be President.
The argument that Obama is not a "natural born citizen" appears to be 100% bogus. He ran against John McCain, who clearly was not born in the U.S. (he was born in Panama somewhere, it is argued he was born outside the Canal Zone and also argued that the Canal Zone really was not U.S. property when he was born -- did the concept of national borders even exist when McCain was born? Did they get a 8 year old boy to watch you being born and break his arm so he would always remember the day?) so just on the basis of "but for Obama we would have had..........." the whole thing is bullshit. "I demand we instate the Panamanian guy over the Kenyan guy!"
Anyway, a little history for you.