Donald Trump's back-to-back immigration-focused events in Mexico and Arizona were an astounding display of political whiplash.

During a surprise visit with Mexican President Enrique Pena Nieto, Trump lavished praise on America's southern neighbor and pointedly avoided publicly insisting that Mexico pay for the wall he's pledged to build along the U.S.-Mexico border.

But in a lengthy and fiery address on immigration in Phoenix hours later, the Republican nominee asserted in no uncertain terms that Mexico would indeed pay for a border wall.

He lambasted millions of immigrants as violent criminals and a drain on the U.S. government. And he vowed that no person living in the United States illegally would have a path to legal status without first leaving the country.