For years Republicans have enjoyed the support of a powerful constituency: conservative evangelical Christians, whose passion on issues like opposition to abortion and support for Israel has aligned them with the party’s agenda. It has been an almost impenetrable voting bloc in recent years, and growing stronger, with more than 80 percent of evangelical voters supporting President Trump in 2016.
Democrats have largely stood on the sidelines as Republicans forged this alliance. But now a group is moving more aggressively to bring evangelical voters and the Democratic Party together as the midterm elections approach.
In the weeks leading up to Election Day, a group of progressive Christians — largely Democrats who are also evangelicals — are organizing small rallies in some 20 battleground House districts across the country. Their goal is to urge Christians to vote for Democrats and counter Trump administration policies that oppose their religious beliefs — especially on immigration, health care and poverty.
The group, Vote Common Good, hopes that shifting even a small percentage of evangelical voters will make a difference at the polls.
“We think they are movable,” said Doug Pagitt, a pastor from Minnesota who is leading the effort. “In the privacy of the voting booth, they might do something.”
The Democratic Party does not have significant resources devoted nationwide to targeted religious outreach, but this effort has support from the Democratic Congressional Campaign Committee, and many Democratic candidates trying to flip Republican seats are participating.
“More Democratic elected officials should be talking about God, and their own personal religious beliefs,” said Representative Ted Lieu of California, a vice chairman for the D.C.C.C. who has informally advised Vote Common Good.
“America has always been a country where faith has played an important role,” Mr. Lieu said. “It’s not a good idea for Democrats to ignore that.”
The rallies, styled as “traveling salvation show tent revivals,” will be held in church parking lots and parks, with beer trucks, musicians and preachers in a bid to encourage evangelicals who have felt alienated from the Republican Party, Mr. Pagitt said.
The challenge is daunting. The initiative is small compared with the formidable ground operation of religious conservatives championing Mr. Trump’s nomination of Judge Brett M. Kavanaugh to the Supreme Court. Those field operations enjoy millions of dollars of financing in battleground states.
The budget for entire Vote Common Good tour is about $1 million. By comparison, each rally held when the evangelist Franklin Graham barnstormed California this spring to drum up the conservative evangelical vote cost nearly as much.
“The progressive left habitually rediscovers the strength of the evangelical vote and tries to counter it,” said Ralph Reed, the chairman of the conservative Faith and Freedom Coalition, which has field teams in 19 states and plans to knock on two million doors by Election Day.
“To be sure, imitation is the highest form of flattery,” he said. “But this effort will fall short because the religious left lacks the intensity, resources and infrastructure built over the years in the evangelical community.”
That isn’t stopping Democrats from trying.
“You are going to have a percentage of evangelicals who realize that the president’s behavior and policies are inconsistent with the teachings of Christ,” said Mr. Lieu, who is Catholic. “The Democratic Party is a very big tent party. You can have lots of different views. We are very accommodating.”
But the party has struggled to connect with white, socially conservative voters, many of whom have views outside the Democratic platform. A year after white evangelicals helped send Mr. Trump to the White House, the House minority leader, Nancy Pelosi, called on the Democratic Party to make room for anti-abortion voters.
Democrats made gains with the group in 2008, when significantly higher numbers of white evangelicals and Catholics, especially young people, supported Barack Obama than had supported John Kerry four years earlier. Hillary Clinton’s presidential campaign hired a faith outreach director, but its program did not include targeted voter outreach, like its youth programs or women’s outreach.
Progressive religious leaders have been increasingly getting involved in politics since Mr. Trump’s election, protesting a range of administration policies, including the separation of migrant families and the ban on travel from citizens of several Muslim-majority countries. In a bus tour before the midterms, a group of Catholic nuns from across the country is driving to Mar-a-Lago, the president’s Florida residence, to mobilize voters around opposition to the Republican tax law.
Vote Common Good is largely funded by Eric Hadar, a real estate investor and developer and Democratic donor, who gave half a million dollars to the project, and who hopes that evangelical defectors might have the best chance of influencing their peers.
“As a white, liberal Jew living in New York, I can march up Fifth Avenue day and night, it won’t have the same impact,” he said in a phone interview. “This evangelical base is really where this is going to turn. Somebody has to focus on these people.”
Democratic candidates participating in the project say they hope to shift the conversation about values in America, which they believe Mr. Trump has betrayed.
“As a child, my family taught me the importance of following the Golden Rule,” said Katie Hill, a first-time Democratic candidate seeking to flip California’s 25th district, outside Los Angeles. She will be attending one of the Vote Common Good rallies.
Republicans, she said, “have shown time and again that they do not follow this most basic value.”
“They have separated families at the border, repeatedly attempted to slash the social safety net and have waged an outright assault on women’s health and early childhood education,” she said.
Gina Ortiz Jones, an Iraq war veteran in southwest Texas who is running to replace Representative Will Hurd, will speak at the group’s event for her district.
“It’s important for people to know that being religious doesn’t always equal being conservative,” she said in an email. “So many people are in favor of Democratic platforms like affordable health care and comprehensive immigration reform specifically because their religion tells them to be kind, compassionate and deliberate in the way they treat others.”