They have one of the worst human rights records in the world.

For them to try and sue the United States, is not only laughable,
but downright criminal.
Their own citizens send home over 20 billion dollars annually because
the government of Mexico cannot, or will not provide jobs for their
own people.
Mexico exports, crime, poverty, and drugs into our country at an
astounding level.
The Mexican Government has let the crime problem in their own
country escalate into what it is now, unmangeable.