Consider, compoanies with plans to locate or grow in Mexico changed their plans based on promises from candidate and President-elect Trump. Except for those that involve executive orders undoing @#$% done by Obama's (and previous Presidents') EOs, many of those promises may not become reality. Why would campaign promises be a tipping point for 10s (maybe 100s, if the trend grows) of millions of $$ of investments?
My opinion is that it has a lot to do with Mexico's social climate and the business climate in the US. Decades of anti- business regs - legislation, bureaucrat-written, and EO - have made the business climate in the US hostile and uncertain (uncertainty = risk, especially when the core of the uncertainty is bureaucrats' caprice). Mexico's government, for several decades, allowed drug and people smugglers significant freedom to move drugs and people into the US, thinking the Yankees would be the ones hurt. Well, they've learned better in recent years, as the criminal gangs settled into Mexican society and made Mexico a very dangerous place for honest Mexican people.
IOW, among all the various factors weighed in a move-don't move decision, the improvements Trump certainly can deliver made the dangers of Mexico and other negatives, in balance, significant enough that staying in the US became the less risky choice. Using a balance scale as a metaphor, Trump takes enough negatives out of the US "pan" to change to balance (and consequent decision).
