Rep. Joe Kennedy (D-Mass.) takes the stage in January to deliver the Democratic rebuttal to President Trump’s State of the Union address in Fall River, Mass. (Brian Snyder/Reuters)
Opinion writer

On Tuesday, the Center for American Progress (CAP) held its annual ideas conference. On one level, it was about rebutting the argument that Democrats don’t have an alternative to President Trump’s populist/nativist agenda. The event gave a slew of possible presidential candidates the opportunity to get in front of prominent Democrats and show off their rhetorical skills. The most successful of these hit on the idea of building an agenda around a common theme.

Washington Gov. Jay Inslee (D) spoke passionately about climate change, using that as a jumping-off point to talk about high-paying jobs, the role of governors (who took up the climate-change fight after Trump backed out of the Paris climate agreement) and the moral obligation we have to our children. “Climate change will no longer be on the back burner,” he vowed. For him that was the starting point to “fashion, articulate and communicate a positive, optimistic, visionary message of economic growth for everybody in our community.”

For Rep. Joe Kennedy (D-Mass.), it was a heartfelt plea for access to mental-health care — in fact, all types of health care. He argued that the means by which we get there can be debated but that Democrats need to take up the obligation to make sure no one falls through the cracks. He bemoaned the fact that in the United States the largest providers of mental health and addiction treatment are jails. He, too, found a theme about which he is passionate and knowledgeable and managed to weave in criminal-justice reform and emphasize his party’s values (e.g. inclusion, social responsibility).

Sen. Cory Booker (D-N.J.) fashioned himself as a wonkish reformer who sees the United States falling behind other countries according to a variety of indices, including economic competitiveness, high school and college graduation rates, and investment in research and development. Lacing his speech with stories about his father, who died six days before Booker was elected to the Senate, he roamed around the stage with a hand-held microphone, showing himself to be the more gregarious of the possible 2020 contenders.

And finishing off the day, the most polished speaker, Sen. Elizabeth Warren (D-Mass.), argued that the country cannot address issues including climate change, education, trade, health care, etc., without first fixing our “crumbling” democracy. She took on gerrymandering, voter suppression, Trump’s effort “to undermine the integrity of our democracy,” and requiring presidents to disclose their tax returns and remove all conflicts of interest. She honestly acknowledged that the purpose of her Democratic Party is to win elections, starting with state legislative and gubernatorial races. Only if the party wins, she says, can Democrats “help fulfill the promise of democracy.”

Finding a way to humanize the candidate and draw listeners is apparently a substantial part of the 2020 playbook. Booker and Warren stressed their humble beginnings; Kennedy told poignant stories of parents of children with mental illnesses. But Democrats’ bigger problem is to figure out a way not to overwhelm voters with a blizzard of promises and programs. Finding an organizing theme or issue, these four potential contenders showed, is one way. Another is rooting policy ideas in expressions of values (e.g. equality, opportunity, inclusion).

It’s far from clear which, if any, of the CAP speakers will run in 2020. The winner may be the candidate who projects earnestness and decency (a fine contrast with Trump) and can organize his or her agenda and message around a single issue or short list of issues. Warren was right about one thing: You cannot accomplish your agenda if you don’t win the election. The corollary might be: You cannot win elections if voters don’t know you and can’t figure out what you really care about.