Democrats mark King's birthday on presidential campaign trail

COLUMBIA, S.C., Jan 20 (Reuters) - Democrats locked in a tight race for their party's presidential nomination will mark the holiday that celebrates Martin Luther King Jr. by seeking the support of black voters.

U.S. presidential candidates, including Joe Biden, Bernie Sanders, Elizabeth Warren and Pete Buttigieg, will spend Monday in Iowa and South Carolina, which are among the first states to hold nominating contests in the race.

Events featuring several of the candidates include a morning prayer service, march and rally in Columbia, South Carolina, dedicated to the slain U.S. civil rights icon. In the afternoon, candidates will speak at a forum on policy issues facing black voters in Des Moines, Iowa.

Monday is the federal holiday celebrating King, who was shot dead by an assassin in 1968 at age 39. Candidates have packed their holiday schedules with multi-state campaigning in the crucial final days two weeks before Iowa holds its Feb. 3 caucus.

"Dr. King didn't give up on the dream, and I'm asking you all: don't give up," Biden told parishioners at the largely black Bethlehem Baptist Church in Columbia on Sunday. The reverend, Anthony McCallum, later told churchgoers to "get behind this soldier" as organ music swelled.

Black voters will play a key role as Democrats choose who will face President Donald Trump in the November 2020 election. They make up more than one in five Democratic primary voters nationally and about two-thirds of the party electorate in South Carolina, meaning candidates have been making regular stops in the state. South Carolina Democrats hold the fourth nominating contest on Feb. 29, before the 14 states holding contests on Super Tuesday on March 3.

"They spend a lot of time here," said JT McLawhorn, president of the Columbia Urban League, a nonprofit organization hosting the candidates at a breakfast in South Carolina on Monday. "You seem them so much you think they live here."

Biden leads among black voters nationally, with about 24% of the vote, compared to Sanders at 16%, according to an average of recent Reuters/Ipsos polls. A quarter of black voters said they were undecided.

King's efforts are credited with the expansion of black voting and civil rights, but many voters see those rights under attack. Democrats have crafted competing polices on voter suppression, economic development and criminal justice reform.

Michael Bloomberg, a presidential candidate who was campaigning on Sunday in Tulsa, Oklahoma, pledged $70 billion to fight poverty in 100 disadvantaged neighborhoods and also announced efforts to help one million black Americans become homeowners over 10 years. (Reporting by Trevor Hunnicutt Editing by Nick Zieminski)