We argue that the leadership selection system, which now gives significant weight to fundraising, helps explain the continuing polarization of the congressional parties. Focusing first on elected party leadership posts, we demonstrate that members will select ideologically extreme leaders over “ideological middlemen” when extremists redistribute more money than their more centrist opponents. We then show that redistributing campaign money also helps ideologues win posts in the extended party leadership, though appointment to such posts by the top leaders (rather than by the caucus) makes the role of money and ideology more complex. Specifically, we demonstrate that top leaders, who are now ideologues themselves, reward the contributions of ideologically like-minded members more heavily than those of ideologically dissimilar members. This produces a more polarized leadership in Congress.