How much you want to bet that they’ve been pulling this type of fraud shit in minority communities forever to make them appear as solid democrats, and had to do it to everyone to even have a chance to elect Biden.
Most immigrants don't get taught a good background in civics beyond the local Democrat office in their area sending them a pamphlet and telling them to vote for this and this and this.
Republicans for the most part don't care about this issue either since 2020 has shown they are content with the rot.
Many of them minorities or immigrants as far as first gen goes are concerned with politics more back at home than here. Minorities before the advent of mail in ballots, have poor turnouts unless it was some friendly charismatic face like Obama.
What I heavily suspect is happening is that their kids or grandkids, most likely are indoctrinated commie subhumans at this point and filled out those mail in ballots, signed it themselves or innocently told them to sign it and mailed in it. And Democrats have been heavily opposing signature matching in addition to voter ID laws.
As far as the black community goes, notice they go more heavy democrat each passing year as their family structure breaks down and more bastards being born and more single family households than before Jim Crow ended. Most of the workers in those heavy urban areas are sheboons and they are the backbone of the current neoliberal Democrat party. Without these baboons, their party has no ground game. The black community has been heavily decimated that its believable to some extent, they are deep blue and in exchange for the gibs, will vote for anything pozzed.
However there is also the old school blacks like in the South that thanks to Congressmen Jim Clyburn, voted hard for Biden. These are usually church going people with stable families. I suspect they are voting for the poz because of their fear of the white man killing them for the lulz and they have a deep hatred of whitey at this point.