Several "grandes écoles" develop programs targeting inner city high schools in order to diversify their recruitment and, more generally, incentivize some students to reevaluate positively their educational ambitions. The impact of these programs cannot be reduced to their mere efficiency in terms of affirmative action. Indeed, the active presence of a grande école in stigmatized urban and educational environments transforms the way students relate to schools by redefining their perception of meritocracy inequalities and discriminations. By analyzing Sciences Po programs in four high schools of the Seine-Saint-Denis, this article intends to shed some light on the way an unprecedented educational offer is perceived, and on the tensions generated by the emergence of educational and social aspirations associated with an acute perception of inequalities.