Pope Leo’s message of compassion for the poor clashes with Javier Milei’s radical economic overhaul, symbolized by his trademark chain saw BUENOS AIRES—Pope Leo XIV is a soft-spoken missionary who rode horseback to minister to the poor in remote corners. President Javier Milei is a chain saw-brandishing populist who slashes government spending, champions unfettered capitalism and calls social welfare “an aberration” akin to robbery.The two men came face-to-face Sunday as the pontiff, born in Chicago but with 20 years of experience ministering in Peru, arrived for a four-day visit in a country where the Catholic Church and the libertarian president...