Autocrats use institutions to `coopt' members of the opposition and neutralize their threat as outsiders. But why do opposition actors allow themselves to be coopted? In Morocco, a constitutional monarchy, the constitution grants elected members of parliament the authority to make requests of government ministers, but it does not require that ministers respond. As a result, horizontal accountability between legislature and executive -- and, correspondingly, legislative effectiveness -- is dependent in practice on the incentives of the ministers themselves to answer a given request. Regime-selected technocrats lack incentives to respond to requests, given their importance for attracting electoral support, and should therefore be less responsive to legislative demands. I test this hypothesis with data on more than 27000 written queries raised by elected legislators in the Moroccan parliament as well as information on the ministers to which they were submitted. I use both matching and difference-in-differences approaches to show that ministers with partisan affiliations are more likely to answer requests posed by legislative deputies than technocrats selected by the regime. The results imply that outside (partisan) participation in government strengthen institutions of executive oversight and that, in contrast, technocrats loyal to the regime negatively impact these same institutions.