Following a recent visit to the border with Mexico, President Donald Trump said the United States is " full ." " Can't take you anymore ," Trump said. "I'm sorry. Can't happen, so turn around. That's the way it is." Fact checkers were quick to counter that declaration . They cited an aging and shrinking workforce, as well as America's slowing population growth, which is now at its lowest level since 1937. And cities like Atlanta and Macon are nowhere near capacity, according to Tim Keane and Josh Rogers.