Pro-democracy uprisings can send a powerful signal to the dictator's allies that the regime's legitimacy is shaking, which may, in turn, trigger elite divisions and, ultimately, regime change. While allying with the regime may grant elites significant advantages, such as privileged access to state resources, opposition movements typically lack the capacity to deliver comparable benefits, and their prospects for assuming power remain uncertain. Why, then, would regime elites defect to support protesters when a dictator can offer more material benefits?

This paper argues that elites defect when they perceive an opportunity to convert mass unrest into electoral support, either by forming alliances with opposition forces or capitalizing on the protesters' grievances. Using novel worldwide datasets on political and military divisions and protest campaigns (1970-2022), we empirically examine the relationship between protests, elite defections, and democratization. Through cross-national analyses and focused comparisons, we find that mass mobilizations lead to elite defections when protests include multiple social groups and are non-violent. Such protests provide a ``safe landing" for defecting elites and a platform to build electoral support for future political competition. However, the type of elite defection matters for subsequent political dynamics: civilian elite defections are more likely to compel autocrats to implement democratic reforms, while military elite defections more often lead to abrupt regime changes. Taken together, the findings reveal when, why, and how mass uprisings successfully lead to the defections that increase democratization prospects.