Drawing on nearly a century of legislative history, this careful account invites readers to think anew about when, why, and how leaders of divided parties wield power in Congress.

For decades, legislative scholars have viewed party divisions as critical constraints on congressional leadership. The more a party's rank and file disagree with one another, the weaker their leaders are predicted to be; as member preferences converge, leader power is thought to increase.

In a powerful corrective to this prevailing view, Ruth Bloch Rubin argues that party divisions are not inherently limiting. Divided Parties, Strong Leaders highlights and examines variation in how members of party factions choose to work together. She shows that leaders of divided parties are well positioned to overcome, and even draw strength from, their divided ranks when the collaborative efforts of their coalitions' competing factions are evenly matched. By contrast, their capacity to get what they want is more limited when one faction has out-collaborated its competition. Presenting detailed case studies of some of the most storied leaders of the postwar Congress, including Speakers Sam Rayburn and Nancy Pelosi, Bloch Rubin analyzes the factional configuration each leader encountered and explains why it mattered for their exercise of power.