Among their other effects, the seismic political events of late 2010 and early 2011 have set off a wave of actual and proposed electoral reforms throughout the Middle East and North Africa (MENA). This wave has touched both countries where long-ruling authoritarian regimes have collapsed and those where existing regimes have (so far) managed to retain power. Throughout the region, even in places not at the center of the recent upheavals—Iraq, Israel, Lebanon, and the Palestinian Authority, for instance—the rules for deciding who will sit in parliament are the topic of intense debate. In all these cases we find the same core challenge for reformers and democratizers: How to open space for new parties and movements to challenge the old ones and gain a voice in the making of laws?