Policy: Trump could have directed the treasury to tax remittances back in 2017. This is how Mexico would have paid for the wall. It was within his power by law. He never did. It was a bad instinct to listen to those who told him not to do it.
Bad policy. It would hurt mostly the poor working Mexicans sending support money to families in Mexico.
I may be a red blooded capitalist, but I resent taxing the poor. Humanity is still alive and well in my heart.
Mexico has already cooperated well with Trump admin by preventing caravans from central America moving freely across the border.