Well it would create a hell of a lot of jobs so in that way it helps. In every other way I doubt it would help, you can still travel by sea from Mexico to the US and the cartels will always find a way. The solution for US its immigration problems is to wage a war against Mexican drug Kartels and put them into Guatanamo, or just kill them. Furthermore the US needs tottrade more with Mexico to get their economy running so that people actually want to live there. Europe's immigration problem is harder though since they need to keep entire Africa and large parts of the middle east happy. And considering Europe isn't allowed to wipe IS from this planet the continent is going to adopt half of Syria. Some are stuck in Turkey but I am sure they will get past Turkey soon enough.
Please excuse my (probally) poor grammar
