The Jerusalem Embassy Act was passed into law by the Congress and the Senate in 1995. The very first sentence in the Act states: "To provide for the relocation of the United States Embassy in Israel to Jerusalem, and for other purposes".
Each President since that time has routinely invoked the six month waiver provided for in the Act. Trump made good on a campaign promise to enforce what the people's duly elected representatives had already made into law. The Obama administration held all three branches of government early in his administration, surely he had the votes to repeal the law.
How you get from that to Benghazi is a mystery to me. It is common knowledge that Hamas has been indiscriminately killing other brown people since 1987. Twenty-one percent of the Israeli population identifies as Arabs (brown people) holding Israeli citizenship and from what I can tell they are not blowing themselves up with suicide vests in crowded public areas and killing civilians because the US is going to change addresses for it's embassy.
Notice how every other president decided not to act on such silly act?