Tuesday, October 4th, 2005 — Mario Pérez, muscular and 16 years old, is a budding carpenter. Next to him is Samuel Sánchez, 32, an experienced roofer. Fed up with earning $4 a day in Mexico, they recently arrived at this tiny town on the Mexican-New Mexican border to start the two-day walk to the U.S. In the wake of Hurricane Katrina, recent moves by the U.S. government may help would-be migrants like Sánchez and Pérez decide where to go. And decisions in Washington are reigniting the immigration debate.