Topics like this are highly controversial, so I am sorry if it steps on anyone's toes.
I happen to agree with him on this.
My position is that we do not have a shortage of laborers in this country. We have a shortage of jobs. More competition for jobs results in lower wages.
Some say that we should import people with degrees, which maybe has some value, but there are stories about companies firing high paid American workers and hiring people from India at half the wage. We have no shortage of people with degrees, since 40% of college graduates have to take a job that does not require a degree.
What is the other thing that we don't have a shortage of? People. The population of the United States has gone up 80% in my lifetime. More people means more strain on resources. Natural resources. Things end up costing more, like land and water.
Hypothetically, will we ever reach a point where the open border advocates think that the country is too crowded? Would it be at 500 million people, or 600 million, 700 million or a billion?