I think that Trump's policy is not totally wrong, because the illegal entry of immigrants and especially the traffic of drugs is a big problem that should be solved to make the american's life more safety. However building a wall is not a good solution. First of all it requires a big amount of money, that coluld be spent in other ways, creating damage to the American economy and above all trying to stop migratory flows in this way is a sign of mental backwardness, bringing to mind Berlin Wall. In fact stopping the illegal migratory is a good idea, because it would reduce delinquency, but without any doubt other ways should be used, also because building a wall would limit the chance to get intoi the USA for those people who go away from violence, poverty and crime. For example: why don't we use our mind, accompained by scientific progress, to boost up security measures in the border in order to make it more impenetrable?
In short why not take advantage of the technological progress of our century, rather than using methodologies that would take us back in time?