"A just law should recognize the contribution of Mexican immigrants to the economy of the U.S."
Mexico's relative prosperity is greatly dependent on the US for its markets, for factories built there which serve US markets, for tourism, for retirees living there, for businesses and homes built by Mexicans living in the US, and the billions sent home by Mexicans living in the US.
So, again, is he prepared to reciprocate with legal status for US citizens in Mexico?
"The U.S. economy needs the Mexican workforce to be able to prosper,"
If he believes that US prosperity is due to cheap labor, will he recommend that Mexico open its borders to Honduran and Guatemalan workers?
"Is he prepared to offer legal status to US citizens in Mexico?"
So what if he is? You're willing to make that trade?