A striking paradox underlies corporate governance reform during the past fifteen years: center-left political parties have pushed for pro-shareholder corporate governance reforms, while the historically pro-business right has generally resisted them to protect established forms of organized capitalism, concentrated corporate stock ownership, and managerialism. Case studies of Germany, France, Italy, and the United States reveal that center-left parties used corporate governance reform to attack the legitimacy of existing political economic elites, present themselves as pro-growth and pro-modernization, strike political alliances with segments of the financial sector, and appeal to middle-class voters. Conservative parties’ established alliances with managers constrained them from endorsing corporate governance reform.