The media routinely frame policy debates as battles between Secular Democrats and religious Republicans. Religion and politics scholars describe growing partisan divisions between religious and nonreligious people as a “God gap” in American politics. And political campaigns indulge in bellicose rhetoric, even alleging that one party has declared a “war on religion.” Combined, these forces fuel a false conventional wisdom that has the Democratic Party captured by Secular activists (e.g., campaign donors and volunteers) and the Republican Party captured by Evangelical activists. Never mind that many Democrats believe in God, attend religious services, formally belong to places of worship, tithe, and pray. Never mind that many Republicans do not. Obvious religious diversity among Democrats and Republicans fails to undermine the “capture” narrative precisely because “capture” implies that those wielding influence in partisan politics do not represent rank-and-file partisans. Political activism is relatively rare and so, in theory, Evangelical and Secular activists could out mobilize other groups and wield influence out of proportion with their numbers. Is the “war on religion” plank in the Republican platform emblematic of outsized influence of Evangelical activists? Have Secular activists “captured” the Democratic Party and declared “war on religion?” These are important questions and this book undertakes a careful investigation of the changing religious composition of partisan activists in order to assess how religious and nonreligious groups are represented in party politics.