Rather than copying the Europeans (there is very little to gain from Europe currently), Mexico and Canada should be encouraged to become part of the United States; for Mexico there could be status of territory longer, until it reaches a status close to the United States (Alabama is the lowest, so that state could be used as a threshold).
I agree. Even if we disregard the constitutional issues, the free flow of Mexican ctitizens to the US and Canada will wreck the middle class. Also, with little exposure and understanding to the fundamentals of our democratic institutions we cannot insure they would be good stewards of our Republic.
But if Mexico (and Canada to some extent) were to become part of the united states, the Democrats, at the behest of the "watermelons" will make them stop Oil production, Mining and Timber operations.
Then we'd be completely 'up the creek and no paddles in sight' rather than just mostly 'up the creek'.