Many of the immigrants to the U.S. are seeking asylum from persecution. In theory the U.S. is supposed to accept such people. The Palestinians are stateless people that want to return to their ancestral lands they were driven from in 1948 by outside invaders. This right is enshrined in both U.N. resolutions and international law.
As for Mexico, the recent election of a left-wing politician offers hope for that country. It should be noted that U.S. drug war policy has made the situation worse in this country. Given the performance of our own government lately, maybe we should limit criticism of the Mexicans.