We produced hydrated clusters of the sulfate dianion, SO42-(H2O)(n) (n = 4-40), using electrospray ionization and investigated their energetics and stabilities using photodetachment photoelectron spectroscopy (PES) at four photon energies. The adiabatic electron detachment-energies of the hydrated cluster dianions were observed to with the number of,water, from similar to0.4 eV for n = 3, the smallest number of water to stabilize SO42- in the gas phase, to similar to5.7 eV for n = 40. The PES features of the smaller clusters are similar, all due to the SO42- dianion, which was found to be in the center of the solvated clusters. The intensity of the SO42-solute PES features was observed to decrease with solvent coverage beyond the first solvation shell (n approximate to 12), whereas a strong high binding energy feature due to ionization of the solvent emerged. For n > 30, the solute PES features almost completely disappeared, and the Water feature became dominant. The photon energy dependent studies allowed us to examine the repulsive Coulomb barrier (RCB), which was observed to decrease as the size of the solvated. clusters. increased. The RCB was also evaluated using a simple electrostatic model taking into account Of both Coulomb repulsion and polarization interactions between the departing electron and the remaining singly charged solvated cluster. The RCB for ionization of water was observed to be systematically smaller than that of the solute SO42-. The trapping of the solute photoelectrons by the solvent and the lowering of the RCB for the solvent ionization channel both contributed to the observed spectral evolution. from dominance of the solute at small n to the dominance of the solvent at large n. Extrapolation of the adiabatic detachment energies of SO42- and the ionization thresholds of water in the solvated SO42-(H2O)(n) clusters yielded bulk ionization potentials for aqueous SO42- and water to be 12.3 and 10.05 eV, respectively.