The most practical way to crack down on illegal immigration is to crack down on the employers. If there are no jobs then the illegal immigrants stop coming and those here will leave. The employers say they need the cheap labor and cannot get American workers to fill the jobs. The reason the labor is cheap is because the government is paying for their healthcare and social services. The government is subsidizing the businesses that hire the illegal immigrants. This is business welfare. American business will do disgusting things for cheap labor. In this case they are relying on government subsidies to meet the needs of the workers they cannot afford on the wages paid. Then they complain about taxes being too high. In the past it was slavery.