Mexico will not pay for the wall, you will
The Foundations of Trump's wall go back over a decade to 2001. The 2001 fence was conceived to keep Islamic terrorists out of the United States because George W. Bush's infinite wisdom assured him that they must be coming from Catholic Mexico where they would surely blend in. It was an extension of the fence that Bill Clinton instituted near Sand Diego in 1994 to coincide with an expansion in free trade with Mexico and the Zapatista uprising against NAFTA. Congressional wrangling over Bush's border fence landed it partial funding in 2006 and the funded part is still incomplete.