Does anybody knows what's offshore manufacturing in Mexico?

'Offshore' is a word we began using in the 80s to mean 'not in the US'. This was after a number of 'globalization' treaties made it cheaper for American manufacturers to move their manufacturing out of the country. It always gave me the idea that these goods were being made on a ship in the middle of the ocean. But what it really has always meant is China, India, Pakistan, Thailand, Vietnam, etc.

NAFTA extended 'offshore' to Mexico, where workers make a lot less, have no legal rights, where environmental laws are just as strict but not enforced,

Possibly so