Yes, the United States should withdrawal from the United Nations, because the United Nations has no standards. The United States also funds a large portion of the operations of the United Nations, and they don't get much to show for it. The United States would be better off pursuing other treaties and peace accords, rather than the United Nations.
The United States and United Nations do not have ideological discrepancies in that both entities want peace and democracy. The major break from the UN came in 2003 when the United States invaded Iraq without the permission of the Security Council since Iraq wasn't threatening anyone except its own people. The U.N. and U.S. have similar missions, even if some countries in the United Nations disagree.