How do formal constitutions impact the prospects for democratization in hybrid regimes, where corruption is typically high and rule of law weak? It is often assumed either that they set “rules of the game,” having effects by being followed, or that they do not matter, being overwhelmed by informal politics. In fact, a logic of collective action reveals that constitutions do matter, but as much by shaping informal political arrangements as by being obeyed. Presidentialist constitutions, through an information effect and a focal effect, generate expectations of future informal power that encourage clientelistic networks to coordinate law-disregarding practices around a “single pyramid” of power led by the president. The information and focal effects of divided-executive constitutions, by contrast, create expectations that complicate the coordination of clientelistic networks around a single patron, promoting “competing-pyramid” politics. To isolate the impact of formal constitutional design and rule out other causes, a tightly controlled process-tracing paired comparison is employed using Ukraine and Kyrgyzstan during 2005–10, explaining why Ukraine's Orange Revolution produced a true democratic opening (even if short lived) while Kyrgyzstan's Tulip Revolution did not.