Malaysia’s largest Islamist party was wiped out in Johor’s state election last weekend, but PAS is now trying to turn that defeat into bargaining power. Its argument is that supporters who had no PAS candidate to vote for helped deliver a landslide victory to Barisan Nasional (BN), the coalition led by Umno, its long-time rival for Malay-Muslim voters. The two parties have spent years competing for influence among Malaysia’s Malay majority, but they have also explored cooperation when it serves...