<span>It's "to reduce the power of the United States"</span>
They think this due to finding fossils, artifacts, footprints, etc in africa leading into south america.
I believed that the best answer here is the Germans, especially protestant Germans from the North of the country. Many of them left from Hamburg and the passage to the US formed an important aspect of the city at the time
There were also big groups of Jews, Slaves and Italians.
Secretary of state and national security adviser under president nixon