Answer:
A policy of favoring native citizens instead of immigrants
Step-by-step explanation:
An example of this was during the 1920's in the US. Many immigrants were coming from Asia and Europe. This made many Americans angry and scared. They were rejecting and harassing immigrant groups. I say this, but they weren't mean to every immigrant group. People coming from countries that are allies to the US, like the English, weren't harassed as bad by Americans.