To Warren, associating with politics risks alienating potential members of the church. "Evangelical is a religious term, but it got co-opted by politics. A lot of people said if that's what it means to be a Christian, or if that's what it means to be an evangelical, no thank you."
At the same time, some younger evangelicals have come to embrace progressive politics. "We've grown up knowing people who are gay. In the older generation it was out there and seemed scary and different. For younger people, these people are our friends, our family members," says Tim King, communications director for Sojourners, a Washington-based Christian organisation that promotes social justice.
Writer Jonathan Merritt, himself an evangelical Christian, agrees: "Today's Christians don't want the test of their faith to be a fight over one particular political issue or another. "Rather, they believe our faith calls on us to speak out on a range of issues, from caring for the environment to protecting the poor, looking out for immigrants and waging peace."
In other words, just as the country has grown more diverse, so too have the values and politics of the evangelical voter.