Aerosols are postulated to alter moist convection by increasing cloud droplet number concentration (N_d). Cloud‐resolving model simulations of radiative‐convective equilibrium show that higher N_d leads to stronger convective mass flux, seemingly in line with a hypothesis that links the convective invigoration to delayed rain formation allowing more cloud liquid condensate to be frozen. Yet, the invigoration is also present in an alternative model configuration with warm‐rain microphysics only, suggesting that ice microphysics is not central to the phenomenon. The key dynamical mechanism lies in the different vertical distributions of the increases in water vapor condensation and in cloud liquid reevaporation, causing a dipole pattern favoring convection. This is further supported by a pair of mechanism‐denial experiments in which an imposed weakening of cloud liquid reevaporation tends to mute invigoration.