Dem presidential candidates introducing themselves to voters

Five Democratic senators vying for their party's nomination to challenge President Donald Trump in 2020 fanned out across the country Saturday to campaign and meet voters.

Kamala Harris of California spent her second straight day in the pivotal early-voting state of South Carolina, holding a town hall meeting in Columbia, the capital. Also visiting the state was Elizabeth Warren of Massachusetts, who met with an estimated 800 voters in Greenville before heading to Georgia — an unusual early stop for a White House hopeful but one that signals Democratic hopes to make inroads in the South.

Cory Booker of New Jersey and Kirsten Gillibrand of New York both focused on New Hampshire. Booker made his first visit to there since joining the race earlier this month, holding a question-and-answer session with more than 400 voters in Portsmouth.

Amy Klobuchar of Minnesota, meanwhile, made her own uncommon choice for early campaigning by visiting Wisconsin before heading to Iowa, home to the nation's first caucus.

And a Democratic heavyweight who's yet to address his 2020 plans, former Vice President Joe Biden, made his own high-profile appearance at the Munich Security Conference.

The Democratic senators stepped up their campaigning during the long holiday weekend at the start of Congress' first recess this year. Their outreach to voters came in the wake of Trump's controversial decision to declare a national emergency in order to unilaterally redirect federal money for his promised wall along the U.S.-Mexico border.

Some highlights from the trail:

CORY BOOKER

The New Jersey senator plans to spend three days in New Hampshire, which casts the first votes in the 2020 primary, and he kicked off the swing with a freewheeling "conversation" that drew questions on health care, the environment and foreign relations.

Booker is one of several Democratic presidential contenders who back legislation that would transition the United States to universal health insurance coverage, but he acknowledged Saturday that compromise may be necessary to get major health care legislation through the Senate.

Booker told voters in New Hampshire there are a "lot of pathways" to achieving universal health coverage, noting that just lowering Medicare eligibility to age 55 would be "a step in the right direction." He said supporters of so-called Medicare for All are "going to have to find ways to advance the ball given the Congress that we have."

Booker brought a personal touch to his first official visit to New Hampshire as a presidential candidate, sharing his African-American family's story of struggling to buy a home in a majority-white neighborhood in the late 1960s as he urged the crowd to "put that indivisible back in this one nation under God." The famously social media-savvy senator stayed long after the event concluded to snap selfies and record videos with supporters.

KAMALA HARRIS

The California senator visited a handful of female-owned businesses in Columbia, South Carolina, on the second day of a swing through the early-voting state.

Harris walked along Lady Street and stopped in Styled by Naida, a black-owned business, and made several purchases, including a wide-brimmed teal hat. The candidate also met with a group of women leaders at a restaurant a block away.

Her visit was organized by Jennifer Clyburn Reed, whose father is Rep. Jim Clyburn, D-S.C., the third-ranking Democratic leader in the U.S. House.

A prominent Democratic activist in the state, Clyburn Reed hasn't yet backed any of the Democrats running for president, and she's organized similar trips for other candidates.

At a town hall in West Columbia, a voter told Harris that most Democrats are looking for someone who will defeat Trump in 2020. The woman became emotional and said she feared the world she was leaving behind for her children and grandchildren, and asked Harris what sets her apart from other Democrats running.

Harris said she believes this moment is a time "that we need fighters on stage who know how to fight - I do - and who have a proven desire to lead."

KIRSTEN GILLIBRAND

Gillibrand, in her second day of campaigning in New Hampshire, issued a rebuke of what she called President Donald Trump's divisive language.

The New York senator and Democratic presidential candidate told a crowd of about 450 people Saturday at Dartmouth College — her alma mater — that the president's worst offense since he was elected has been to "dehumanize people" and create a climate of fear and hatred, especially toward immigrants.

Gillibrand said Trump wants Americans "to be afraid of one another." She insisted "that's not who we are."

Gillibrand, who took questions from the audience, said she favors a single-payer health care system modeled on Medicare and would take on climate change by incentivizing the creation of renewable energy. She added that she was optimistic that "common sense" gun laws would pass now that young voters are calling for change.

JOE BIDEN

The former vice president isn't officially part of the 2020 presidential race, but he bolstered his case for a potential candidacy by speaking to an international audience about the need to restore America's ability to claim leadership in the world.

Without saying President Donald Trump's name, Biden said in a speech at the Munich Security Conference that current policies do not reflect the country as he perceives it.

"The America I see values basic human decency, not snatching children from their parents or turning our backs on refugees at our border. Americans know that's not right," Biden said.

He said the U.S. doesn't want to turn its back on its closest allies and cherishes democracy, the rule of law and a free press, telling the conference that the America he sees "stands up to the aggression of dictators and against strongmen who rule by coercion, corruption and violence."

A former chairman of the Senate Foreign Relations Committee, Biden is likely to lean on his international-relations credentials should he choose to join the increasingly crowded field of Democrats running for their party's presidential nomination.

While he has yet to disclose any timetable for deciding whether to enter the race, Biden has two public events slated for later this month, the first at the University of Pennsylvania and the second in Delaware, his home state.

And he isn't the only well-known politician on the fence about the Democratic primary. Among the others are Beto O'Rourke, a former Texas congressman, and Sherrod Brown, an Ohio senator.

Associated Press writer Juana Summers in Columbia, South Carolina, contributed to this report.