WASHINGTON (AP) — Speaking before a gathering of black leaders on Capitol Hill this week, Sen. Kamala Harris offered guidance on when Democrats should fight President Donald Trump and Republicans.

"What I've found myself recently saying is this: 'If it's worth fighting for, it's a fight worth having,'" the California Democrat and potential presidential candidate said, pausing, before repeating the phrase once more. "And I say that because I think sometimes there is a conversation that suggests that before we decide we're going to engage in a fight, some might say, 'Well, let's sit back and consider the odds of winning.'"

"No," Harris continued. "If it's worth fighting for, it's a fight worth having."

Energized by their success in last week's midterms and courting potential primary voters outraged by the actions of the Trump administration, virtually every Democrat considering a White House run is talking about fighting in one form or another — and trying to prove he or she is prepared for the match.

Some, like Sen. Elizabeth Warren of Massachusetts, have taken aggressive stances that suggest a willingness to take on Trump directly. Others, such as Sen. Sherrod Brown of Ohio, talk about fighting for workers and espouse an aspirational vision of America. And former Massachusetts Gov. Deval Patrick, another potential presidential candidate, urges a higher form of politics that moves past the bitter rancor of the moment. In the process, all the possible presidential contenders are offering signs of how they would approach their candidacies.

Dan Pfeiffer, who was a senior adviser to former President Barack Obama, said the best Democratic campaign will be the one that can "raise the stakes."

"You need someone who is tough enough to take on Trump, for sure. But what you want is someone who is inspiring," he said, cautioning that it's still early and potential candidates could change their approach.

"If your message is 'They punch me in the gut, I punch them in the face,' that is not an inspiring message," he said. "We have to make this election about big things, and we have to inspire people."

Last week's election showcased a variety of strategies.

On election night, Warren declared that Trump and his "corrupt friends" had spent two years "building a wall of anger and division and resentment." In her speech, she referenced the "fight" ahead more than two dozen times.

"Tonight, as the first cracks begin to appear in that wall, let us declare that our fight is not over until we have transformed our government ... into one that works, not just for the rich and the powerful but for everyone," Warren said.

Sen. Amy Klobuchar, a Minnesota Democrat and potential presidential candidate, spoke of an electorate that voted for the way politics can and should be.

She described a final meeting with the late Republican Sen. John McCain of Arizona in which he pointed to a passage in his book that said, "There is nothing more liberating than fighting for a cause larger than yourself."

"That is what Minnesota voted for today," Klobuchar said. "Minnesota voted for patriotism, Minnesota voted for tolerance, Minnesota voted for people who believe in opportunity."

In a victory speech in Ohio, where Brown notched an easy win even as other Democrats there struggled, he appeared to test a populist pitch for the White House.

"When we fight for workers, we fight for all people, whether they punch a clock or swipe a badge, earn a salary or make tips. Whether they are raising children or caring for an aging parent," he said.

Later, Brown urged the nation to look to the Midwest, and particularly Ohio, and to take note of how his state celebrates workers.

"That is the message coming out of Ohio in 2018, and that is the blueprint for our nation in 2020," he said.

Diane Feldman, a pollster for Brown's 2018 race, said Brown tends to talk "about who he's for, rather than who he's against," and described his message as an "affirmative one."

"There's going to be a discussion about whether the Democratic Party defines itself in opposition to Trump or whether the Democratic Party really has something to assert about who we're for or what we're for and what that means," Feldman said. "While we're all against Trump, we also need to be clear on what we would change in ways that would be helpful to people."

Perhaps no one in the potential field has demonstrated the impulse to fight than Michael Avenatti, the lawyer for adult-film star Stormy Daniels and a vocal Trump critic. Avenatti, who has said he is considering a 2020 run, said in his first early state speech as a potential political candidate that Democrats "must be a party that fights fire with fire."

Avenatti was arrested this week in Los Angeles on allegations of domestic violence, which he has denied.

Tom Steyer, the billionaire investor and Democratic activist who is considering jumping into the 2020 race himself, said Democrats need someone who can explain to voters "not just how stupid and misguided what's going on right now is," but who can also speak to the opportunity ahead of the country to course-correct."

"It's a hell of a good thing to run your mouth, but when the time comes, the American people need someone to produce, someone who understands what's going on and is not just flapping their gums," Steyer said.

Donna Edwards, who represented Maryland in Congress for four terms before giving up the seat to run for Senate, said she hoped that Democrats would not "take on Trump by being Trump," and would be capable of speaking to the broader interests of Democrats and left-leaning independents across the country.

"I think as Democrats we have to be smart — we're always so good at doing policy," Edwards said. "We live and die on our policy, but we have to have that unique combo of the policy and the personality that fits the entire country, and I think that's going to be the challenge."