This page hosts supporting documentation for our paper at Journal of Experimental Social Psychology: Dealing with government dysfunction: Perceived electoral system brokenness explains the effects of high and low perceived polarization on support for fixes. In the "[files][1]" tab, you can find pre-registration documents for each of our studies, which contain the hypotheses, planned analyses, and materials. You can also find a list of [deviations][2] from our various pre-registrations, which documents any decisions we made that differed from our original, pre-registered plans. **Abstract:** In five pre-registered experiments, we demonstrate causal effects of perceptions of political polarization and, especially, electoral system brokenness on desire for inclusion of a third party candidate and support for potential fixes to the electoral system. We first manipulated perceived issue polarization between two candidates in a fictional election to be high, medium, or low and showed that the high and low polarization conditions, compared to the medium condition, evoked greater desire for inclusion of a third candidate. Then we established that perceiving the electoral system as broken statistically mediated the effect of high and low polarization on greater desire for inclusion. We next demonstrated experimental mediation in two ways: via a manipulation-of-mediator design (Pirlott & MacKinnon, 2016) in which we manipulated the proposed mediator (i.e., perceived electoral system brokenness) and, separately, via a moderation-of process design (Spencer, Zanna, & Fong, 2005) in which we simultaneously manipulated both perceived polarization and perceived brokenness. Both perceived issue polarization (high and low versus medium, and high versus low, excluding medium) and perceived brokenness exert causal effects on greater desire for inclusion of a third party candidate. When people perceive high and low issue polarization and when people perceive brokenness in the electoral system they support actions that pose potential fixes to the brokenness, such as including a third-party or independent candidate in elections. [1]: https://osf.io/fdwmq/files/ [2]: https://osf.io/5zyus/