It is not just Mexico. There is no way that anyone in this country can compete with Bangladeshis that work for $4 a day. As Marx says, capitalism is a race to the bottom. It was less true in his day, because shipping was slow and there were no factories in backward countries.
In China, they have workers who live in hotbed dorms where they share a bed in three shifts and work 10 hours a day, six days a week