Elections are contentious by design, but contentious election outcomes—from democratic backsliding to widespread protests and violence—occur regularly and represent significant challenges to both domestic and international stability. This review essay explores three specific outcomes of contentious elections (i.e., failed democratization, democracy protests, and election violence) using three recent, influential books on these topics. It highlights several, overlapping causal mechanisms, including those focusing on structural characteristics, actor behavior, and election cycle dynamics. It also explores four cross-cutting themes (i.e., democratization, electoral history, structural constraints, and money in politics), as well as three areas for future research (i.e., overlooked actors, election integrity, and international factors).