I am not an expert in this area ... but in case you do not know the story behind MS-13, read / watch this. It certainly a scary situation but an easy one on which to inappropriately latch arguments and instill fear against immigration in general Those people on the border to Mexico are seeking assylum by entering the U.S., for the most part, are not part of MS-13.
The article from BBC says that Trump is blaming Obama but Obama's administration is NOT to blame. At this point no one in particular is to blame, not even Trump, except he is using the situation to fan fear and to manipulate his agenda and that of his cronies and followers.
Also, for the sake of argument, MS-13 is what happens when people have no where else to turn, no place to grow their families, poor health, little food, horrible living conditions, etc. Watch the short video attached to this article. Imagine yourself and the people you love having to live under those conditions. Revolutions come when people have nothing to lose!
There is no excuse for MS-13's violence and criminal disregard but I think that in reallity this is what happens when people are so alienated and at risk that there is no hope. They are fighting for their lives in the only ways they know how, and they have created new standards on how they relate to their own, to society, to life.
In a parallel universe and in many of the same ways, Trump's supporters are also feeling so alienated and at risk they they see little or no hope. For them the "American Dream" has turned into a nightmare. They are for the most part still operating within societal norms and standards of behavior and decency (but lower and lower) and their discontent is also growing.
Without trying at least to understand MS-13's viewpoint (while not condoning their attrocities) they and similar renegade organizations will continue to grow. People like Trump and his cronies will continue to use them as a fear factor. We will see not only the continued breakdown in our civilization as we know it but we will also witness the move towards more of a military state which will the continued diluting of everyone's human rights as an excuse to contain the breakdown and violence in societal norms.
I have not even begun to broach the idea that the U.S. is not alone, the world has become a nighmare of a place to live for so many people in so many countries.
I do not have any solutions to offer but do know that we need to somehow come to grips with the fact we are all in this together: from black to white to red to yellow, from Jew to Christian to Muslim, from the richest to the poorest, from the educated to the ignorant, from the best behaved to the worst behaved, from the governed to the government.
In some ways we cannot blame the current atmosphere of life in the U.S. and the world on Trump, it has been a long time sneeking up on us, as well as blatently shouting but going unnoticed and unheard. We can and should deplore Trump and his cronies and supporters for using this frightening, devistating situation to manipulate their own discontent, power and wealth.
We must begin to support each other in ways that respect individual differences, build us up without dehumanizing, listen to each other so as to better understand who we are, support our needs not manipulate them. Making "America Great Again" is a reality, it is just that Trump and his people are using that sound bite to their own purpose and in effect, whether you want to admit it or not, making America less and less.