During recent party congresses in China and Vietnam, two highly anticipated candidates for promotion were sidelined. In China, Bo Xilai was arrested for corruption and stripped of his party membership. In Vietnam, Nguyen Ba Thanh remained a provincial leader with little opportunity for promotion to the Politburo. Existing arguments about promotions under authoritarian rule are unable to explain these outcomes. In particular, both candidates were competent and well connected. This cuts contrary to the expectations of both performance-based promotion and factional promotion theories. We argue that these candidates were sidelined due to a previously under-theorized factor in promotion contests—their ability to mobilize personal followings. Amidst a literature that has focused almost exclusively on intra-elite conflict, we argue that elite–mass linkages are critical. In particular, the public profile of top leaders is important for regime legitimacy and mobilization. However, when individuals become exceptionally well known they become threats to the single-party system. We test this argument on promotions in China's 18th Party Congress in 2012 and Vietnam's 11th Party Congress in 2011, using original data on Internet search queries and media coverage among contenders for promotion. Our approach offers new insights into the strategies authoritarian politicians use to stay afloat as well as the mistakes that sink them when competing for power under one-party rule.