theres also countless studies that show immigrants make the economy better. A better economy benefits black people.
You have to take a step back and ask yourself why black people and poor immigrants are competing over the same jobs. And why its beneficial to white supremacy that black people fight with immigrants.
This really isn't our fight. We help white supremacy by joining in on it.
No, it is our fight. You are engaging in "the sum of all parts helps us all" fallacy whereby you think a rising tide helps all, but this is not necessarily true as a function of the US population relates to the US economy.. While studies show immigration helps the country, this does not necessarily mean those benefits stretch to blacks and overcome the negatives which concurrently occur as a function of immigration. The majority of the country is WHITE and they DON'T COMPETE with Mexicans nor face the same challenges black men do.
Illegal immigration enriches and helps white employers and white people (ergo, the country since most of the country is WHITE) who don't compete with Mexicans for jobs but disdvantages and disenfranchises black people and black men whom compete with Mexicans for jobs (black men only make up 6% of the country and blacks only make up 12%). The overall benefit Mexicans provide to the economy does not transfer enough to blacks to overcome the negative effects Mexicans have on blacks. Thus immigration ultimately harms black people more than it helps. If this were not true, the studies would not correlate black unemployment and incarceration with increased illegal immigration.
Now, as respects your "why are blacks even competing with Mexicans" point, that doesn't matter. Blacks all around the world compete with people like Mexicans for jobs. Winning those jobs for blacks is how we win. Losing those jobs is how we lose. Asking "why" is pedantry.