there are two sides:
no discrimination in relation to people on the one hand, it is unfair
the second side: i'm against migration, because i do not want another people to live in my country where I pay taxes and build the opportunities for my family and children, not for others.
I'm very curious about what country you are from. Almost all countries have a long history of immigration. Did your ancestors never migrate? I doubt that. Migration is natural it has been happening throughout all the history of the world. If you are from a poorer country, maybe you are getting immigrants from a country that's even poorer. That could be a problem. If your country has good immigration policies, they can recruit many highly qualified immigrants than can bring much to your country's economy. Migration can be a very good thing for both parties, the immigrant and the receiving country.