Pope Francis’s weekend trip to Morocco aims to highlight the North African nation’s tradition of Christian-Muslim ties while also letting him show solidarity with migrants at Europe’s door and tend to a tiny Catholic flock on the peripheries. Francis will address the first two items on the agenda Saturday when he begins his 27-hour visit to Rabat, the Moroccan capital. He’ll tend to the third when he wraps up the visit with a Mass and a meeting with Moroccan clergy on Sunday. “Morocco has always been a pioneer in initiatives of dialogue with Christians,” said Abdellah Boussouf, an Islamologist and...