Ed Sheeran’s tour of North and South America was plunged into chaos Tuesday when four of his supporting acts abruptly quit in solidarity with the rapper Macklemore, who was dropped for making pro-Palestinian comments on stage. Hours after Sheeran posted on social media about Macklemore’s ousting and attributed the decision to the tour’s promoters, Irish acts Aaron Rowe and Beoga, the Danish band Lukas Graham, and Finneas posted on social media that they were leaving the tour. Rowe and Lukas...