The people who are feeling hope and optimism about America’s future, do not see what you describe. They are, indeed, part of the problem, with their foolish pollyanna complacency.
I can tell you from daily experience that the overwhelming majority of immigrants I see have no interest whatsoever in assimilating. In CA, we have people who were born here who do not know how to speak English... and see no reason to learn it.
They and their children have no interest in anything American and don’t really care too much about what happens here. They have not bought in to our country in any way. Our laws and system mean little to them. America is a source of income; that’ it.