The strategic use of the judiciary against political rivals, often termed lawfare, has historically characterized authoritarian regimes and and is now increasingly a source of concern in democracies. A central empirical challenge is distinguishing uniform enforcement of wrongdoing from the selective targeting of political opponents. Using a regression discontinuity design and newly assembled data from Pakistan, we provide causal evidence on the existence and extent of lawfare. We show that opposition politicians face systematically greater judicial scrutiny, with effects large enough to crowd out potentially legitimate anti-corruption efforts. By contrast, government affiliates facing comparable allegations are far less likely to be pursued, underscoring the asymmetric nature of enforcement. These disparities reshape political competition: convictions of opposition politicians eliminate the well-documented incumbency advantage, weaken challengers, and tilt the playing field toward incumbents. In this way, institutions meant to pursue accountability can be redeployed as instruments of political victimization, distorting both justice and electoral competition. Although democratization is often expected to reinforce rule-based institutions, our findings show that lawfare endures under both democratic and military rule alike, transforming courts from instruments of accountability into tools of political repression.