Currently available political economic tools are not very useful for predicting the outcomes of real-world policy problems. Researchers have limited information on which to assign parameters to the mappings from policies to outcomes to utilities or to represent the political process adequately. We present a method for evaluating the viability of political alternatives in complex settings and apply it to an ongoing California water policy debate. Certain options would be "robustly politically viable" if stakeholder groups trusted that they would be implemented as negotiated. Once we incorporate institutional mistrust into the model, none of the alternatives are robustly politically viable.