How do you convince migration supporters that migration can be bad?

If you take an example of the unprecedented decisions regarding migration support taken in Germany in September 2015, there were inevitable consequences hurting German society and the pro-European politicians who took these decisions. Right wing AfD party in Germany has harshly criticized the decision about opening borders and letting new migrants freely enter the country pointing out at inability of the German state to control movements of the newly arrived migrants on the country's territories and consequent decrease in security. At the same time if migration support at the country of migrant's destination does not have any infrastructure that newly accepted migrants could use, migrants would not be able to receive any shelter and receive basic care. And in case local population has been brainwashed and warned against migrants, the newcomers might expect feeling isolated and hostile. Differences in legal standards could often not allow migrants to have their degrees and professional experience be recognized in another country. Therefore one needs to thoroughly analyze the situation related to the popular attitudes towards and the average living standards of the migrant population in one country in order to understand the living conditions and possible level of social integration that he or she could expect upon relocation.