It's both. And immigrants help the wealthy class become even richer by providing cheap labor while everyone makes up the rest in social security payments.
You know who's not paying their fair share into social security in any country? It's the rich, yo! It's the rich! By a wide margin!
To be perfectly clear, I don't care one way or the other about more immigration or less immigration.
What I am saying is that compound interest and the ability to purchase assets is going to continue to draw wealth away from everyone except the ultra wealthy, and immigration policy has effectively nothing to do with that.
Calling on everyone to hate each other is going to prevent us from acting together to solve this problem. We could instead work together, unionize, vote for policies and politicians that won't let the ultra wealthy continue to hoard their gold like dragons.