Title III, Ch. 1, Sec. 301(a), paragraph 7 of the Immigration and
Naturalization Act of 1952, aka the McCarran-Walter Act, specifies which
children born abroad to parents of whom only one is an American citizen
is himself an American citizen:

The following shall be citizens and nationals of the United State
at birth:

(7) a person born outside the geographical limits of the
United States
and its outlying possessions of parents one of whom is an
alien,
and the other a citizen of the United States who, prior to
the birth
of such person, was physically present in the United States
or its
outlying possessions for a period or periods totaling not
less than
ten years, at least five of which were after attaining the age
of fourteen years


The snarky boy, "iaranrod", pretends that this only applies to to
children born to married couples, only one of whom is an American
citizen. The snarky boy then assumes that if the couple were not
legally married, then a child born to them would be a citizen. That's
*WRONG*. Section 309 actually places *greater* restrictions, not fewer,
on establishing the American citizenship of the child if the parents
were not married:

CHILDREN BORN OUT OF WEDLOCK:

Sec. 309. (a) The provisions of paragraphs (3), (4), (5) and (7) of
section 301 (a), and of paragraph (2) of section 308, of this title
shall apply as of the date of birth to a child born out of wedlock
on or after the effective date of this Act, if the paternity of such
child is established while such child is under the age of twenty-one
years by legitimation.

http://library.uwb.edu/guides/USimmi...stat%20163.pdf

So, regardless of whether or not Hussein's parents were married, he
would not have been born a citizen had he been born outside the
geographical limits of the United States and its outlying possessions:
regardless of his mother's marital status, she didn't meet the necessary
requirements for giving birth abroad to an American citizen under the
law effective in 1961: QED.