Spanish Prime Minister Pedro Sánchez faces growing pressure from within his Socialist Party to call an early election, before scandals besetting his four-month-old minority government undermine a surge in voter support. Riding high in the polls, Sánchez aims to serve a full term to mid-2020 as he focuses on approving next year’s budget and countering renewed independence moves in the Catalonia region. But last week, his science minister was forced to deny media reports he cheated on his taxes, days after a recording emerged of the justice minister using a homophobic slur. Two other ministers have already been pushed out,...