Here we go with the "they do the jobs Americans won't do".
Look, if those businesses were willing to pay more than 1/2 minimum wage, they'd get plenty of Americans willing to do the job.
My youngest son was let go from a job at a restaurant so the owner could hire 4 illegals for the same amount they paid my boy. My son was more than willing to bus those tables and wash the dishes.
Minimum wage laws weren't put into place so businesses could break the law by hiring illegals, and breaking it again by paying them less than minimum. If a business can't survive when paying their employees a reasonable wage, then they don't need to exist. People might have to go back to doing their own mowing and trimming, oh no, the World might come to an end!
Our economy, in its present neocon destroyed state, can't continue to absorb immigrants at this kind of rate. At several times in this Countries history, we needed the influx of immigrants to continue to expand. Now, it will only serve to further erode our economy and standard of living.

BTW, the main distinction between how our Grandfathers and Great Grandfathers came into this Country is that they did it LEGALLY. In the late 1700's immigration into the US was wide open, as long as you were white. There have been many modifications to the immigration laws in the US, but they came when they would be best for the Country.

Why don't we try getting rid of the BS free trade and try a little fair trade. Make other countries that want to do business in the US, bring their wages and standard of living up to meet ours. If they don't, charge an appropriate tariff so they would have to compete with US companies on equal ground. Make them produce a product that is competitive in quality to compete here and not just cheaper. They all still want to trade with us, we are the biggest consumers on the planet.