There is nothing in Article II disqualifying a person from the Presidency who by action of foreign law has foreign citizenship. The only citizenship requirement is that he be a natural born citizen of the United States. Anyone who maintains otherwise is an "emanations from the penumbra" guy, just like those who find a right to abortion in the Constitution, and should be held in similar low regard.
The logic of the above article would give foreign states a method to meddle in the U.S. Presidential election. For example, if the Soviet Union had not wished Ronald Reagan to be President of the United States, all they would have to do is pass a Soviet law stating that Ronald Reagan was a Soviet citizen, and that Soviet law does not allow Ronald Reagan to renounce said Soviet citizenship. Abracadabra, Ronald Reagan could not be President of the United States. An obviously absurd state of affairs.
I would agree that dual citizenship might be something that the American people could take into account in the selection of a President. If the American people do not want a person with dual citizenship to be President, they will have to accomplish that at the ballot box.
It is legal for a child of less than 18 years of age to have dual citizenship in Indonesia. At age 18 that child must choose of which nation he/she wants to be a citizen. Barack moved to Hawaii when he was 9-10 years old.
In 1981 Barack Obama said he went to Pakistan with a college roommate who had overstayed his student visa. At that time U.S. citizens were prohibited from traveling to or from Pakistan. The only way Obama could have gotten into and out of Pakistan was by using his Indonesian passport (which would clearly state his religion as Muslim).
He was have been around 19-20 years old. That is a sure declaration of citizenship when you use a passport as an adult. He declared his allegience to Indonesia.
He isn’t eligible, under Articl II of the U.S. Constitution, to be our President. As a lawyer specializing in Constitutional law he knows it too.