Many of them have lived here for decades, work peacefully, and have built lives. Many of them have married citizen spouses, and also have children who are citizens.
They are friends, neighbors, and colleagues. They are often the best and most ambitious among us.
It would be an ethical, moral, and humanitarian catastrophe to suddenly expel all of them.
It would also be an economic disaster, as this population forms a disproportionate fraction of the labor force.
The price of goods and services would skyrocket if not outright be lost from the market forever. Inflation would obliterate savings.
The US immigration system is wildly irrational and violates the rights of American citizens. It must be radically reformed.