Conclusion
This conclusion highlights the importance of PACs in twentieth-century American political development. The emergence of partisan PACs, initially formed by major interest groups, played an important and neglected role in fostering the polarization of American politics—a phenomenon that has raised concern in recent decades. Seeking to reconfigure party politics around specific policy issues—more broadly, to realign the party system along an ideological dimension of conflict—these PACs helped make the parties more distinct and more deeply divided over time. They did so via electoral tools and tactics that are now ubiquitous in political life but are rarely probed in scholarship. A focus on PACs thus illuminates the very mechanisms through which party change was brought about, as much as its wider meaning. The book concludes with a consideration of contemporary US politics, in which PACs continue to play a prominent role.