The main overhaul plan under consideration in Congress would grant legal status and citizenship to illegal immigrants, which many in the GOP see as a form of amnesty for people who broke U.S. law.
Groups favouring stricter immigration laws say the reforms under consideration would exacerbate financial problems for state and local governments and would lead to higher levels of illegal immigration.
But over the years, foes of illegal immigration have chipped away at the policies to the point where keeping families together is no longer a key consideration.