At least a half dozen declared or potential presidential candidates will attend events and talk about what King's legacy means to Americans in 2019. Among them is former Vice President Joe Biden, who, amid intense speculation over whether he'll seek the presidency, will make his first public appearance of the year at the National Action Network's annual King breakfast in Washington with its founder, the Rev. Al Sharpton, and Martin Luther King III. Former New York Mayor Michael Bloomberg, still considering a bid, is also on the schedule. And New York Sen. Kirsten Gillibrand, who jumped in the 2020 race this week, will appear with Sharpton later in the day in Harlem.
Meanwhile, Sens. Cory Booker of New Jersey and Bernie Sanders of Vermont will attend events in South Carolina, where black voters make up 60 percent of the Democratic primary. And Massachusetts Sen. Elizabeth Warren is expected to speak in Boston, where King attended seminary.
The King holiday marks the first time in the early days of the Democratic primary that so many White House hopefuls are holding public events on the same day. That reflects the wide-open nature of the 2020 field, which is likely to include several candidates of color for the first time. Some Democrats say the party's presidential nomination could ultimately go to the person who best navigates racial issues.
"On King Day, they should all have messages for how we enable people who live on the outskirts of hope to come back into the circle of opportunity," said Democratic strategist Donna Brazile. "That's what Dr. King would do."
Politics loom large over this year's remembrances. In a tweet earlier this week, President Donald Trump again mocked Warren, using the slur "Pocahontas" and referring to the 19th-century Battle at Little Bighorn and Wounded Knee Massacre. Rep. Steve King, an Iowa Republican, prompted bipartisan criticism with racist remarks that questioned how white supremacy and white nationalism became offensive terms. King has said his comments were taken out of context.
Against that backdrop, Sharpton said it's crucial for the candidates speaking on Monday to directly address racial politics. "It will be telling if they do not represent an alternative to the situation we're in," he said, referring to the country's racial divisions. "They've got to deal with the issues in a way that we know that they're not just making a one-day-a-year speech."
"The challenge," he added, "is how you distinguish yourself without appearing disunifying." Last fall's midterm elections show the potential for assembling such coalitions, with several minority congressional candidates winning in mostly white districts. And while black Democrats suffered defeat in Georgia, Florida and Missouri, the gains they made show promise for minority candidates eyeing 2020.
Andrew Gillum, who lost his Florida gubernatorial bid in November by 30,000 votes, has met with several potential 2020 candidates in recent weeks, and he said the topic of race has come up. The issue was unavoidable in his own bid to become Florida's first African-American governor.
"Under no circumstance could I deny my race and how that has informed who I am today," Gillum said. "People aren't stupid. I don't want anyone to pull any punches about how race shows up in society and how it impacts us."
But the balance is tricky, particularly for candidates of color, he said. For them, navigating race "is like walking on a lake freshly frozen," Gillum said. "You never know what step might take you under."
Regardless of their race, Democratic candidates will have to find a way to appeal to a broad coalition of voters with a message that energizes a diverse base without alienating whites whose support will also be crucial.
In a video accompanying the launch of her presidential exploratory committee, Warren included a chart outlining the disparate household wealth between white and black families and called for an economy that "works for all of us."
A similar video from Gillibrand included broad appeals such as a pledge to support the middle class, along with a clip of her saying, "It is outrageous to ask women of color to bear the burdens of every single one of these fights over and over and over again."
Alabama Sen. Doug Jones, who is white, defeated African-American challengers in his primary before going on to win a special election in 2017, becoming the first Democrat in a generation to represent the solidly Republican state. Jones said his background as the prosecutor who brought the 16th Street Baptist Church bombers to justice was an advantage with black voters, but added that he also had a proven track record on issues of equality, respect and voting rights long after that case.
"Folks are going to be looking at candidates and saying, 'Have you got a history of this, or is it just the first time you're looking at it?'" Jones said in an interview. "I talked about issues important to the African-American community, but they were really a lot of the same issues that were important to the white community: health care, jobs, education, those kitchen-table issues that cross all manner of racial lines and get to the heart of the matter."
Authenticity will be important for candidates, regardless of color, in delivering a message that resonates with voters, Jones said. "If you're talking to the black preachers in the Black Belt of Alabama, you ought not be afraid of giving the same speech to the Chamber of Commerce in Madison County," he said. "It's a matter of messaging. You've got to be who you are. ... Not trying to pander to anyone, not to appear that you're pandering to anyone or not trying to minimize your support."
Whack is The Associated Press' national writer on race and ethnicity. Follow her work on Twitter at http://www.twitter.com/emarvelous.