Next week, the Senate will begin making changes to and, hopefully, improve the immigration-reform legislation I introduced with several colleagues last month. This part of the process is a chance to fix America's broken immigration system and end today's de facto amnesty for those who live here illegally. It will also show that Washington can work when leaders listen to the American people and invoke their wisdom in debates and legislative work. In January, I outlined my principles for conservative immigration reform in these pages—principles that guided the drafting of this legislation. These include securing the borders; requiring all employers...