Interesting article in Political Science Quarterly, and currently ungated as well.
Juan D. Lindau, "The Drug War's Impact on Executive Power, Judicial Reform, and Federalism in Mexico." Political Science Quarterly 126, 2 (Summer 2011): 177-200.
There is no abstract, but the first two paragraphs lay it out:
The drug war, and the Mexican governmentʼs increasingly assiduous pursuit of drug-trafficking organizations, complicates the countryʼs institutionalization of democracy in a number of ways. The intensification of the drug war in Mexico has come during the waning decades of an authoritarian regime and the first years of a nascent democracy. The drug war hinders fundamental democratic institutional development, or more accurately, fosters the expansion of non-democratic institutions and practices. These effects come against the backdrop of genuine democratic gains during the last two decades, including the development of transparent and credible electoral procedures, the emergence of an assertive, divided legislature, judicial reforms, and increases in substantive federalism.
Juxtaposed against this real democratization, the drug war preserves certain authoritarian proclivities of the Mexican state and fosters corruption and impunity, reducing the efficacy of judicial reforms and complicating the professionalization of the judicial branch. The security crisis engendered by the drug war fosters expanded executive power. At the same time, the drug war undermines federalism, increasing the power of the central government vis-à-vis states and municipalities.
The argument is ironic. Democratization left a power vacuum that drug trafficking organizations moved into fill. Subsequently, the state's efforts to combat those organizations stalled or reversed a number of gains in democratization as re-centralization took place.