Immigrants spur the economy by increasing the population, which boosts overall demand for products and services. In turn, this demand spurs new jobs for both immigrants and natives, and the economy grows. Decreasing legal immigration would reduce this demand and put a drag on employment for everyone.
The chart above divides the population by the number employed here in America.
Note that we have fewer people working now than we did in 2000.
As you can see, our population has gone up.
Yet it has not led to an increase in the number of people that are employed.