The combination of illegal aliens and the employers who break the law by hiring them is where the problem is. The politicians don't really want the problem fixed or they would enforce the laws already in place.
The effect of having these illegal workers here is it brings down the wages of all workers in this Country. The people in this Country worked hard to bring the standard of living up to one of the best in the World. Now we have a corporate and political pairing that's bent on destroying that standard.

If the politicians had any balls, they would institute a fine of at least $30k for every illegal alien an employer hires, and enforce the fines.
They would also level the trade deficit field by, for example, taking a companies goods that are produced in a Country that pays its workers 30% less than here, and charge a 30% tariff on their goods imported and sold in the US. Free trade agreements don't raise the workers wages and conditions in other countries up, it lowers them in our Country.