In accepting the invitation of President Enrique Pena Nieto to fly to Mexico City, the Donald was taking a major risk.

Yet it was a bold and decisive move, and it paid off in what was the best day of Donald Trump's campaign.

Standing beside Nieto, graciously complimenting him and speaking warmly of Mexico and its people, Trump looked like a president. And the Mexican president treated him like one, even as Trump restated the basic elements of his immigration policy, including the border wall.

The gnashing of teeth up at the New York Times testifies to Trump's triumph:

"Mr. Trump has spent his entire campaign painting Mexico as a nation of rapists, drug smugglers, and trade hustlers. … But instead of chastising Mr. Trump, Mr. Pena Nieto treated him like a visiting head of state … with side-by-side lecterns and words of deferential mush."