In May, President Bush unveiled a plan that would station 6,000 National Guard members on the Mexican border over the next two years to help stem the flow of illegal immigrants across the nearly 2,000-mile border from California to Texas. While these troops would serve primarily in support roles, some governors have expressed concern that the Guard would become increasingly stretched by this additional deployment. To alleviate this concern, Bush said National Guard troops would rotate into this assignment during the two- to three-week training sessions that guardsmen are required to undergo each year. This rapid turnover means that tens of thousands of guardsmen will shuffle through border patrol posts in Arizona, California, New Mexico and Texas. Read the full report

Russell Heimlich  is a former web developer at Pew Research Center.