Firstly, those who believe "everyone is equal" should not have any truck with the idea that some illegals are more important than American citizens, because they shouldn't be believing anyone is more important than anyone else.
Secondly, if these people experience inequality in their home countries, I'm very sorry for them, but that does not mean that Americans have to pay to redress that, because Americans are in no way completely responsible for it.
Thirdly, America is wealthy, but its wealth, and its capacity to absorb immigrants, does have a limit. That is basic math. 12 million extra people mean 6-7 million extra jobs and/or welfare payments; 3-4 million extra homes, 2-3 million extra school places; which means hundreds of thousands of extra teachers; thousands more eating places, thousands of square miles of living space; and so on and so and so on. California is already on the brink of bankruptcy.