Immigrants are very often people from different ethnic and religious groups than you, who you have to compromise and deal with because they are present in large numbers in your poltical jurisdiction in a way they were not previously. Being angry at them for creating the conditions under which you have to compromise with them is normal.
It's normal, but misguided to direct your anger at them. It's so normal it's the usual path the frustration is channeled, often with conspiracy theories such as "the replacement" etc.
Compromising and dealing with people is what life's all about, but it's easier to hate than to build consensus and harmony.
And of course, some people exploit these misguided tendencies because they want people not to focus on systemic inequalities that are the root of their problems, and instead blame everything on some other group of people that's different from them. Or because fanning the flames works as a ladder for them.
