USAID is an entity created by Congress, a separate branch of government, via legislation, not via executive order. It lives in a separate universe, in legal terms, than entities created by executive order. This is called separation of powers. The executive branch cannot make substantive changes to an entity created by Congress due to separation of powers. It also cannot prevent moneys allocated by Congress to USAID from being spent, due to impoundment. These are tenets for you to learn, not argue about. The world was not invented with your birth, when you fell out of the coconut tree. You live in an inheritance, a world in which all of this- laws, independent branches, etc etc was already worked out, over many distinct countries and legal regimes over thousands of years.
