Reminds me of the Romer model. Ideas have increasing returns to scale, compared with capital accumulation. Hence the more "scientists" (does not really refer to just scientists) we have, the more a nation will grow. This is because ideas are nonrivalrous, and my use of them does not affect your use. The parallel to this is as the user angeleno points out, higher education for undocumented students and their potential ability to use their degrees would help the U.S significantly; since more ideas would be produced and the country benefit off these innovators.