Donald Trump could build up to seven walls on the US-Mexico border with the money raised by imposing tariffs on all Mexican imports until next October.In fact, by July, the U.S. would have enough money to pay for a wall, budgeted at about 21,600 million dollars.If the Mexico tariffs plan designed by Trump is applied in retaliation for the supposed null actions of Mexico to control the Central American migration, by October there will have been added 161,847 million dollars not foreseen. Enough to build seven border walls and...