Editorial: Fear and a whole lot of loathing in Mexico. Can Donald Trump possibly find common ground south of the border?

Making a wholly unexpected side trip, Donald Trump’s presidential campaign circus has traveled south of the border. Even more surprising, Mexico let him in.

The Republican standard-bearer flew to Mexico City today for a private audience with President Enrique Peña Nieto, a meeting of two massively unpopular political figures. It’s hard to see what either gains from it, other than trying, on the part of Trump, to look like a statesman willing to meet face to face with the leader of a country and a people he has maligned. Or maybe he is just, once again, seeking to seize hold of the news cycle through an audacious act. Regardless, it’s an astounding development in a political campaign of astounding developments (beginning with Trump’s rise itself), and though it will keep the punditry machine in full roil for a few days, it’s hard to see a side trip south of the border will resonate anywhere except on a irony meter.

Is there common ground between Trump and Mexico? Trump has insulted Mexicans in the most despicable terms, and has exploited American nativism for his own political gain, in part by promising to deport 11 million people (mostly Mexicans) living in the U.S. illegally. He also says he would end the constitutional definition of a citizen as anyone born on U.S. soil, a change that would preclude children born in this country from being Americans unless one or both of their parents were already citizens. He also says he’d force Mexico to pay for his silly border wall (which, if it existed now, he breached simply by flying over it), and has pledged to renegotiate NAFTA, which has helped Mexico build its economy.

For Peña Nieto, the calculation is murkier. Last week, he extended invitations to Trump and his Democratic rival, Hillary Clinton, and there are reports that his administration was surprised when Trump accepted. Peña Nieto is in trouble politically (approval rating of 23%), and meeting with Trump (approval rating of 2% in Mexico) isn’t likely to help. It could be he wants to distract attention from a burgeoning scandal concerning whether he plagiarized the thesis for his law degree.

But as Peña Nieto noted himself, Trump is one of two candidates who stand a chance of leading the U.S., and if Trump wins, they will have to work together to continue an international relationship that has long, deep and occasionally fractious roots. Mexico is the U.S.’ third-largest trading partner (and the U.S. is by far Mexico’s top export destination), and the social and familial connections -- particularly with Southern California -- are considerable. Although Peña Nieto earlier compared Trump to Hitler and Mussolini, he has since softened his tone toward the Republican presidential nominee.

The private meeting precedes Trump’s much-anticipated speech on immigration Wednesday night in Phoenix. Will he back away from his draconian call for mass deportations, including American-born dependents of the undocumented, and to only let the “good ones” back in? Will he recognize the folly in his planned wall? Will he actually change anything, or double-down on his hateful rhetoric?

And the biggest question: If he does shift his stance on immigration, will he actually mean anything he says in Phoenix? Trump’s loose connection with the truth -- he flat-out denies he’s made statements that are easily found in online videos -- requires us to take any policy utterances with a large grain of salt. Still, we’ll watch. So far, Trump has been a candidate of many surprises, most of them lamentable. And a trip to Mexico followed by a speech on immigration can’t undo the damage he’s already done to political discourse. Even a softer, gentler and perhaps more statesmanlike Trump can’t change the underlying character.

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