During brief press remarks following a USMCA speech in Pennsylvania, Vice President Mike Pence outlined the current status of “talks” between the U.S. and Mexican officials.
The vice-president affirms several times that President Trump is “firm in his position” to see Mexico step-up and do more to stop the mass migration of illegal aliens from Central America.  If you think about it, against the context of the USMCA, the Trump position to confront Mexico is absolutely the right approach.
Mexico wants the USMCA trade agreement, and they want to be united with the U.S. and Canada on trade and collaborative economic benefits.  However, simultaneously Mexico has repeatedly said it will not join the “Safe Third Country” agreement held by the United States and Canada, where asylum seekers must apply for refuge in whichever country they first arrive in, as each is considered safe.

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[It’s worth noting that Pence is likely under a lot of pressure from Tom Donohue and his friends within the U.S. Chamber of Commerce. Pence deserves credit for standing up to his traditional tribe.]