Nope. Just his mother is enough.
My beef is that I believe he was born in Kenya and even if his mother had returned to the US she still failed other rules.
For persons born between December 24, 1952 and November 14, 1986, a person is a U.S. citizen if all of the following are true (except if born out-of-wedlock)[7]:
1.The person's parents were married at the time of birth
2.One of the person's parents was a U.S. citizen when the person was born
3.The citizen parent lived at least ten years in the United States before the child's birth;
4.A minimum of 5 of these 10 years in the United States were after the citizen parent's 14th birthday.
For persons born out-of-wedlock (mother) if all the following apply:
1.the mother was a U.S. citizen at the time of the person’s birth and
2.the mother was physically present in the United States or one of its outlying possessions for a continuous period of one year prior to the person’s birth.[8] (See link for those born to a U.S. father out-of-wedlock)[7]