USAID is a soft power clearing house for the US government. Long ago, the state department, CIA and DOD were all running soft power operations and in an effort to consolidate them, USAID was created. It is supposed to get people to like the US government. Before Obama, it wasn't supposed to be operating "on US soil" but he changed that. By the time Trump was elected, it would be hard to say that it was effective at its task. If anything, it seemed to be doing the opposite of what it was supposed to be doing.