This clearly symbolic image (after all, whatever you think of him, Trump knows how to use the media and how easily the public fall for media crap) always struck me as bizarre. After all, there is, technically, a border between the USA and Mexico (probably mainly for Mexicans to keep loonies like Trump out of their country). I've been there - 30 years ago I even interviewed guards and spoke to wetbacks. Trump is just, symbolically, saying he intends to improve those borders which have always been and will always be porous. It's like May or Farage announcing they will build a moat around the island of Britain. Why?