August 2, 2006: Since the United States sent 6,000 National Guard troops to help patrol the border with Mexico two months ago, arrests of illegal border crossers has declined about 20 percent compared to the same period last year. Despite the presence of these troops, there were still some 160,000 arrests, of illegal border crossers, in the past two months. Fans of illegal immigration say that many of those attempting to cross illegally are simply going to other parts of the border. But no one really knows.