Global demographics, not domestic policy, will control who comes and who goes. In Washington, politicians are trying to reform America's immigration system, again. Both President Obama and Republican Sen. Marco Rubio (R-Fla.) are proposing "paths to citizenship" for an estimated 11 million illegal immigrants. Other proposals abound, including finishing the border fence, creating a better E-Verify system for employers and passing the last Congress' Dream Act. All of these ideas, however, fundamentally misunderstand immigration in America: Future immigration is probably going to be governed not by U.S. domestic policy choices but by global demographics.... --snip-- ...that Puerto Rico's fertility rate...