As the race heats up to determine which candidate will take on President Donald Trump for the Democrats in the next election, there is a surge of energy on the American political left. One aspect of that appears to be a growing movement for a revitalized Christian left, but it is unclear how much influence it could have. There is a long history in the US of combining the principles of Christianity, Islam and Judaism with progressive political ideas, including the civil rights movement. However, middle-aged and younger Americans have experienced a political environment with a strong connection between conservative Christianity and the Republican Party, with no real equivalent on the left. This began around 1979, when conservative Christians created the Moral Majority and began what became an effective, well-organized movement that united conservative Christianity and the Republican Party. Today, many Americans associate Christianity — especially evangelical Christianity — with the Republican Party. White evangelical Christians are an essential part of Trump’s political base, with a Pew Research Center poll from March showing that 69 percent of white evangelical Protestants approved of Trump — a slight drop from earlier polls but still very high. However, Christians with more liberal political perspectives are increasingly pushing back on the conservative dominance of the Christian political narrative in the US. This is not entirely new. There have been intellectuals and activists who have combined Christian principles with liberal politics, but their influence paled in comparison to conservatives. Shifting demographics have offered some hope for liberal Christians. While polls have shown that younger Americans are less likely to be religious than older Americans, among those who are religious, middle-aged and younger Americans are significantly more likely to be moderate or progressive — and much less likely to be conservative. Trump’s election breathed new energy into the religious left in terms of political engagement. The widespread evangelical Christian support for Trump was appalling to many liberal Christians, particularly since Trump seemed like an unlikely candidate for Christians to support, given his own personal history and his apparent lack of interest in religion before his campaign. Many liberal Christians now feel deep anger toward Trump himself and his administration’s policies. While many liberal Christians previously believed that it was best to keep religion and politics separate, since Trump’s election more have embraced the idea that, as Christians, they must engage in politics — and utilize the language and principles of their faith in doing so. In recent weeks, Democratic candidate Pete Buttigieg has provided further impetus for liberal Christians. Unlike many Democratic politicians, Buttigieg is very intentional in talking about his personal faith and making the argument that Christian principles support a liberal political perspective. One of the challenges for a religious left movement is defining what it is and who it includes. The potential constituency for such a movement is very diverse, including Protestants and Catholics of various races and ethnicities. It includes people with strongly opposing views on abortion and homosexuality.The unifying theme for the religious left draws on Christianity’s messages about love, Jesus’ call to take care of the vulnerable in society, and Jesus’ example of going against the traditional authorities and norms in order to reach out to “the least of these,” as the Gospel of Matthew says. Buttigieg and other leading voices also call for a form of Christian engagement with politics that is more inclusive, defined less by who and what Christians oppose and more by who and what they support. Key policies for this group of Christians include welcoming refugees, the humane treatment of immigrants, support for the poor, access to health care, and other social justice issues. The Christian left actively embraces working with Jews, Muslims and other faith communities to advocate for progressive policies. It remains unclear whether the collection of voters, intellectuals and religious leaders that make up the Christian left are building the types of organizations and alliances that are crucial to gaining significant political influence. At a minimum, the religious left is years away from developing the type of sophisticated political structures that the religious right has built. Another challenge is wariness on the American political left about mixing religion and politics. The left tends to emphasize the importance of separation of church and state more than the political right. Even many liberal Christians worry that mixing religion and politics could erode secular democracy and negatively taint religion. There is concern that trying to tie Christian principles to a left-wing political agenda undercuts the role that religion can play in transcending political and social divides. On the other hand, there is a sense among liberal Christians that they need to reclaim their faith. There is a desire to better balance Christianity’s role in US politics and to assert that conservative political interpretations of Christianity are not the only valid ones. Among younger generations, the perception that Christianity is deeply tied to conservative social and political views has turned many people off religion, and liberal Christians hope to challenge that perception. Some conservative Christians are reacting angrily to Buttigieg and other politically active liberal Christians; sometimes questioning whether they are “real” Christians. It remains to be seen whether liberal Christians can gain political traction, and whether bringing more liberal Christian views into politics better balances the relationship between politics and religion or fuels deeper divisions.