DT has caused America systemic degradation of its institutions. Immigration is just one aspect.
Even though DT is out of power, his followers occupy all levels of government. That's why IMHO we see the progress against the capitol rioters is so slow. Because there is unbelievable amount of distrust.
And thus it is a delicate and huge challenge in front of biden to undo that damage. I would be ecstatic if Biden admin can even cut half the damage. I do not expect them to restore anything back to normal.