Biden is making a move on immigration — he has to because, as it stands, it's the Republicans issue to win on. Will it matter? For both the election, and at the border, this remains an open question. 

It's tempting to think of immigration in black and white terms — or, rather, in terms of the left and the right. But what Hein de Haas, author of "How Immigration Really Works" and a leading researcher in the field, teaches us is that many of our common beliefs about immigration — coded red and blue — could benefit from a hard look at the data.

His work shines a light on the connection between migration and the decline of the US middle class, while explaining that we got to where we are not because of the invisible forces of a nameless group of migrants, but because of the very real, very American, policy choice we have made.