Castaneda helps change the Bush administration's views on immigration reform. Castaneda is convinced throughout the piece that the economic and social integration of North America will happen over time. Castaneda is firm on this point, even as he is consistently frustrated by Washington's inability to reach a reasonable consensus on bipartisan strategies. Ex Mex seems to offer a modern Mexican perspective written for Mexicans. In the first chapters, Castaneda uses several testimonies to explain how Mexican immigration patterns developed dramatically in the 1990s. Castaneda wanted to underline the issue of seasonality from which he took the second part of the title: "From migrants to immigrants". He talks about the reduction in the return of immigrants to Mexico due to much stricter border control guidelines. This has also dramatically increased Mexican immigrants to the United States, legal or illegal. They are approximately “11 million in 2007 and are estimated to be 6.2 million