You bet it would in the long run. But many Americans who do not care about America's future are consumers who favor the idea of exploiting illegal workers because it keeps commodity and service prices down in the short term. But Most third world illegals come to the U.S. for personal economic reasons. Most do not come to cherish our democratic system. Illegal aliens are better off in the U.S. doing lousy menial jobs than they are in their own country.
Illegal aliens pay taxes that benefit the economy.
But here in California it hasn't. For example, the feds had to bail out the L.A. County hospital system several years ago and the county hospitals are now again headed for another crisis. The evidence shows that the net results are that illegal immigrants cost the taxpayer significantly more than they pay in taxes. Illegal aliens have a good work ethics. If it means that illegals will allow themselves to be exploited, then they have a good work ethic.