Anti-immigrationists reply that if you use sufficient force, you can completely stop immigration, and except perhaps in the case of refugees fleeing brutal persecution in a neighboring country, you are never obliged to open your door. Turkey may have a moral duty to allow desperate Syrian refugees to cross its border, but if these refugees then try to move on to Sweden, the Swedes are not bound to accept them. As for migrants who seek jobs and welfare, it is totally up to the host country whether it wants them in or not, and under what conditions.
