The "desperate" need for workers is over-hyped. A lot of kids are underemployed, and wages are way down already. The labor supply would adjust itself if our elites would let it. One thing that isn't hyped is the overwhelming amount of Hispanic immigration we've had over the past 40 years. Census data shows us the undeniable change it has brought to our demographics. Looking around in a city like LA should be all that it takes to realize that we don't need any more "migrant" labor from Mexicans.
A good point. Businesses can adjust.
The current problem of illegals undercutting wages also keeps the good corporate citizens at a disadvantage to unscrupulous employers, and the push for legalization is seen as the only remedy. What does it tell you? Businesses dont beleive enforcement will happen.
In fact, we need to import less of the low-wage low-skill workers and more of the knowledge-skill workers, who create more jobs via ripple effects on our economy.