From left: Sen. Bernie Sanders (I-Vt.), Sen. Kamala D. Harris (D-Calif.), and Starbucks executive chairman Howard Schultz. (AP photos)

The future of the Democratic Party has been booking late-night TV gigs, waking up for morning drive-time radio and showing up at watering holes in rural counties to try out new material.

Before the start of a 2020 Democratic presidential campaign, at least 25 candidates — mayors, governors, entrepreneurs, members of the House and Senate — have hit the road to workshop their vision, experiment with catchphrases and test policy ideas that could keep President Trump from winning a second term.

Many deny that their actions have anything to do with a coming presidential run, but they unmistakably play off the chords of campaigns past, seeking a way to break through a political maw that has been focused more on the latest actions of the president and the coming midterm elections.

“I don’t want to speak to Democrats only,” says Sen. Cory Booker (D-N.J.), who recently appeared on ABC’s “Jimmy Kimmel Live” to riff on the Founding Fathers’ vision of patriotism and love. “I’m talking to us as Americans, about how this is a moral moment.”

In front of policy conferences and campaign rallies for congressional candidates, former vice president Joe Biden has been updating his own paeans to the middle class, repeating his thematic refrain that “America is all about possibilities.” Sen. Elizabeth Warren (D-Mass.) has broadened her calls for people to “fight back,” and Sen. Kamala D. Harris (D-Calif.) has demanded that “we must speak truth.”

“This is like taking the play to Topeka and New Haven to see what works before you even get to Broadway,” said David Axelrod, a former strategist for President Barack Obama who hosts would-be candidates for public forums at the University of Chicago. “The season hasn’t opened.”

Democrats are starting to angle for 2020, even if they deny it

At stake in the rehearsals is nothing less than the future of the Democratic Party, which has yet to congeal around a positive vision. Party leaders privately talk about the next two years as a potential pivot point for what it means to be a Democrat, like the tumultuous 1968 Democratic convention or the business-friendly realignment that followed President Bill Clinton’s nomination in 1992.

“The Democratic trajectory right now is more uncertain than it has been since I started in politics in the ’80s,” said Simon Rosenberg, a longtime Democratic strategist at NDN, a think tank. “And I think no one has a leg up.”

The questions are big ones — of style and policy — that can only be answered in the story told by the candidate who eventually captures the party’s imagination.

Some promote a vision of a youthful future, while others speak of their own wizened experience. Some use the language of the private sector, while others have begun to promote guaranteeing public-sector jobs for all unemployed Americans. Some speak of class as the defining American divide, while others ­focus first on racial and gender inequality. Some are brawlers ready to take on Trump, while others pose as healers to call the country back to better angels.

They have begun to grapple with the sense that Trump’s presence has erased all of the old rules, even for Democrats, and that the party should consider looking outside the standard roster of governors and senators — perhaps to a business executive-entertainer like Oprah Winfrey, who has so far resisted calls for her to run, or a mayor.

“My theory of this election is you are going to basically have a swing back,” said Julián Castro, the former mayor of San Antonio and secretary of Housing and Urban Development, who has been traveling the country talking about “expanding opportunity.” “People are going to look for someone who can unite the country instead of divide it, someone they can trust.”

Los Angeles Mayor Eric Garcetti, who will speak Sunday at a graduation in the first primary state of New Hampshire, has ­focused on another theme, the wisdom that can be brought to Washington from those working outside the dysfunctional city. “At this moment you have leadership in D.C. that defines itself by dividing us and subtracting us,” he says. “In local communities, we still are decent people who are about the politics of addition and multiplication.”

Starbucks executive chairman Howard Schultz, a businessman who has long considered a presidential run, has recently started a personal office as he pulls back from day-to-day control of the company. His public speeches drift far afield from the coffee business.

“This is not a time for isolationism, for nationalism,” he said Thursday at the Atlantic Council. “This is not a time to build walls. This is a time to build bridges.”

The potential candidates preach both national and party unity, decrying the “false choices” between appealing to white Midwestern voters and the more diverse and urban Democratic base. But in the next breath, they sometimes demonstrate how many different routes there are to reach that goal of restitching the Democratic coalition ripped apart by Trump.

“The economy doesn’t have a good answer for people who ­haven’t gone to college, and it hasn’t had an answer for a long time,” said Center for American Progress president Neera Tanden, who will host at least 10 potential candidates Tuesday for a policy conference. “Trump proved a wrong answer beats no answer.”

Late last month, Harris stopped by the Breakfast Club, one of the biggest morning shows in urban radio, to discuss the importance of blacks voting in the recent victory of Sen. Doug Jones (D-Ala.). “The math is that a white Democrat won in the south because of black women,” she said, simplifying a close election that was turned by many factors.

A couple weeks earlier, Montana Gov. Steve Bullock (D) traveled the back roads of Iowa, boasting that 20 percent of his voters in 2016 also marked Trump on the same ballot. “I show up, as simple as that is,” he said in an interview. “I don’t have the luxury of going places where people think exactly like me.”

Mayors and governors have been talking up their own liberal records of innovation in the states, aiming to contrast their competence to the dysfunction of Washington. “We have demonstrated that a policy ecosystem of progressive economic development works,” said Washington Gov. Jay Inslee, who has been traveling the country as chair of the Democratic Governors Association. “We have blown up the Republican trickle-down message of Donald Trump.”

Mayor Pete Buttigieg of South Bend, Ind., who is working on a book due out next year, has anchored his pitch in a broad vision of Democrats as “the party of everyday life” — a good job, health care and education included. “We’ve got to realize that a lot of this has to do with style,” he said. “That should be fairly obvious — we have a president who doesn’t even have an ideology, only a style.”

Others like Colorado Gov. John Hickenlooper have begun to speak about the failures of past administrations, as the party struggles to identify an economic message in an age of low unemployment, strong market performance and continued kitchen-table insecurity.

“I think we also have to not be afraid to look back with an honest eye,” he said of the effects of global trade. “What happened in the 1990s with outsourcing was really government malpractice. As a country, we didn’t deliver for our citizens.”

Rep. Tim Ryan (D-Ohio), who hails from Youngstown, has argued for a focus on the economic threat of China, while cautioning against new government programs that displace the private sector. “We can be hostile to monopolies, oligarchies and concentrations of wealth,” he said. “But we can’t be hostile to capitalism.”

After the 2016 election, Sen. Bernie Sanders (I-Vt.) announced that he had been “humiliated” that the Democratic Party could not appeal to the white working class, “where I came from.”

Since then, he has tried to focus more on healing the rifts that emerged between him and minority communities. It has been a sometimes rocky road, such as when he awkwardly described Obama as a “charismatic individual” during a speech in Mississippi on the anniversary of the Rev. Martin Luther King Jr.’s assassination.

Sanders says he has been learning since the last campaign. “The situations in African American communities are obviously very different than they are in Vermont,” he said. “What I learned was that we have a criminal justice system that is not only broken, but is significantly racist.”

Warren has also been reaching out to the black community in an effort to stamp out the impression, left from the 2016 campaign, that the financial regulatory issues at the core of her life’s work are not a central cause of minority communities.

“I know I haven’t personally experienced the struggles of African American families, but I am here to say that no one can ignore what is happening in this country,” she said in a recent address to the Rev. Al Sharpton’s National Action Network, which began with a discussion of housing ­policy and ended with her calling out, “Can I have an ‘amen’ on that?”

Party leaders have also been floating a set of new policy ideas, which go beyond the 2016 promises of expanded health-care coverage, tuition relief for college students and more infrastructure spending. Booker has introduced a bill to both legalize marijuana and expunge the records of those with marijuana possession convictions. Sen. Kirsten Gillibrand (D-N.Y.) has put forward a bill that would allow the U.S. Postal Service to take on banking functions, including short-term loans to undermine the costly payday-loan industry.

Several potential candidates, including Booker, Gillibrand, Harris and Sen. Jeff Merkley (D-Ore.) have signed on to a bill that would create a pilot program, offering guaranteed jobs paying at least $15 an hour in 15 high-unemployment communities. Sanders has said he is working on his own version of the same program.

Others have charted more moderate paths. “I love Bernie, but I’m not Bernie Sanders. I don’t think 500 billionaires are the reason we’re in trouble,” Biden said in a speech May 8 at the Brookings Institution, in which he proposed free community college tuition, limits on worker noncompete clauses and efforts to broaden the geographic reach of venture capital.

Most of the potential candidates, including other outsiders such as entrepreneur Mark Cuban, have said they will wait until after the midterm elections to make any announcements about their 2020 plans. “It’s not about Donald Trump,” Cuban wrote in an email explaining his view of the coming campaign. “He is who he is and everyone knows who he is.”

Others, such as Hickenlooper, say they really don’t know if they are ready to put their families through the two-year strain of a campaign. For the moment, they still have time to work that out.

“What did St. Teresa say?” Hickenlooper asked rhetorically, referencing a quote often attributed to the saint. “ ‘There are more tears shed over answered prayers.’ ”

David Weigel contributed to this report.