Venezuela’s authoritarian leader, Nicolás Maduro, was declared the winner of the country’s tumultuous presidential election early Monday, despite enormous momentum from an opposition movement that had been convinced this was the year it would oust Mr. Maduro’s socialist-inspired party. The vote was riddled with irregularities, and citizens were angrily protesting the government’s actions at voting centers even as the results were announced. With 80 percent of voting stations counted, the...