Our immigration system is out of control. We can't hold the line at the border. We can't prevent the hiring of unauthorized workers. Despite our tough rhetoric, an estimated 11 million illegal immigrants feed a vast underground economy that makes a mockery of the rule of law. No wonder the public is hungry for tougher enforcement — and no wonder politicians from House Republican leader Tom DeLay (R-Texas) to Sen. Edward M. Kennedy (D-Mass.) are responding with promises to crack down. ....The truth is that beneath the bluster we're ambivalent about enforcing immigration law because we know that if we...