Although prior research has documented a divergent relationship between leader Machiavellianism and abusive supervision, it fails to uncover the underlying mechanisms of this relationship. Drawing from trait activation theory as the overarching theory, we develop and test a dual-path model to examine how and when leader Machiavellianism leads to abusive supervision. Specifically, we theorize leader perceived threat to hierarchy (power-threatening process) and perceived power dependence on subordinations (power-sustaining process) as two parallel mechanisms through which leader Machiavellianism affects abusive supervision. We further identify leader position power as a boundary factor that influences the power-threatening and power-sustaining processes. Using multi-wave, multi-source data collected from 175 supervisors and their 763 subordinates, we found that Machiavellian leaders were more likely to perceive high threats from subordinates to the existing hierarchy, though this threat perception was not significantly associated with abusive supervision. Additionally, Machiavellian leaders were also more likely to perceive high power dependence on subordinates, which in turn reduced their abusive supervision. We further found that leader position power strengthened the positive effect of leader Machiavellianism on leader perceived threat to hierarchy, but did not weaken the positive effect of leader Machiavellianism on leader perceived power dependence on subordinates. The implications of our findings are discussed.