I assume Trumps supposed antisemitism is the reason for:

"In what critics framed as Orwellian ‘up-is-down, down-is-up’ remarks from the State Department on Tuesday, U.S. Ambassador to the United Nations Nikki Haley and Secretary of State Mike Pompeo officially announced that the U.S. is withdrawing from its participation in the U.N. Human Rights Council, claiming the body responsible for upholding international standards for human rights was no longer “worthy of its name.”

Haley—who has steadfastly refused to acknowledge the human rights violations of close U.S. ally Israel, including multiple charges regarding that country’s alleged war crimes carried out against Palestinians in the Occupied West Bank and Gaza—said the withdrawal from the council was necessary “because our commitment does not allow us to remain a part of a hypocritical and self-serving organization that makes a mockery of human rights.”
A strange way of supporting antisemitism methinks!