A wall between Mexico and the US is a very sad symbol. However, every country has a right, and a duty, to know who enters that country. Right now, that is not happening at the US Mex border, except where there are already walls and official border crossings. The other sad thing is that so many  Mexicans feel the need to get into the US to escape poverty. Instead of so much outrage Mexico must work even harder to provide opportunities for their citizens.  The border wall will also partly hinder drug smuggling as well as the weapons smuggling from the US into Mexico.