Pre-print, Working paper: Inequality in political participation and influence has strongly increased in recent decades. In this paper, we focus on three aspects of political inequality: the increasing concentration of both political and charitable donations, the growing gap in descriptive representation, and the persistent lack of substantive representation. Based on the existing literature as well as on novel evidence, we relate these aspects to the recent widening of turnout inequality. We then examine novel forms of participation-e.g. the rise of small donors in the US-and the efficiency of policies aimed at improving representation. Finally, we discuss new avenues for research.