"Apparently, we are done with it since we are giving it to the Mexicans."

One could also phrase that. "....giving it BACK to the Mexicans.".

U.S. Grant:

"For myself, I was bitterly opposed to the measure, and to this day regard the war [with Mexico] which resulted as one of the most unjust ever waged by a stronger against a weaker nation."
If you vote for government, you have no right to complain about what government does.