Birth Abroad Out-of-Wedlock to a U.S. Citizen Mother: A child born abroad out-of-wedlock to a U.S. citizen mother may acquire U.S. citizenship under Section 301(g) INA, as made applicable by Section 309(c) INA if the mother was a U.S. citizen at the time of the child's birth, and if the mother had previously been physically present in the United States or one of its outlying possessions for a continuous period of one year.It's likely that Obama's parents were not legally married since his father was already married.
That has already been discussed and the law as you just stated it is the most recent version that Obama is not covered by.
Just so I know why is it so important that we break treaties, congress has ratified, and we have signed in regards to international law just so that Obama can be our next president?
No.
His father's prior marriage would not affect the question of whether the father and mother were in "wedlock" for purposes of Sec. 1409(c). If the Stanley Ann/Obama Sr. marriage were contracted in the US, it would be voidable; and it would have constituted the crime of bigamy. But as between the parties and those whose rights were affected by validity (children), the marriage would be treated as effective until terminated by a court. The actual extent of the rights of the parties might differ state to state but as to the federal citizenship wedlock issue, the courts would hold they were married.
Further, if they were married in Kenya, the marriage would presumably be valid under local law and there would be no doubt it was an effective marriage for purposes of the wedlock issue. The first wife might be grounds for divorce in the US but that wouldn't affect validity of the marriage.