The concerns of minority voters will loom large in the next debate between Democratic presidential candidates Hillary Clinton and Bernie Sanders.
The tight race moves next to Nevada and South Carolina, two states with large Latino and black populations.
Mrs Clinton is trying to rebuild her campaign after Mr Sanders decisively won the New Hampshire primary.
She received a much-needed endorsement from an influential bloc of black Democrats in Congress on Thursday.
The Vermont senator won the New Hampshire primary by 22 percentage points and lost the Iowa caucuses narrowly, but both states have nearly all-white populations.
He now faces the challenge of finding votes among the sizable Latino and black electorates in Nevada and South Carolina.
Mrs Clinton has acknowledged that she needs to do more to appeal to young women and new voters, demographic groups that have so far come out in force for Mr Sanders.
But the former secretary of state has strong support among Latinos and African-Americans and is expected to do well in Nevada and South Carolina.
A recent NBC News/Wall Street Journal/Marist poll in South Carolina gave Mrs Clinton a lead of 74 over Mr Sanders’ 17 percent among black voters.
On Thursday, the political action committee of the Congressional Black Caucus (CBC) publicly endorsed Mrs Clinton as their Democratic presidential candidate, giving an extra added boost to her campaign.
“We must have a president that understands the racial divide, not someone who just acquired the knowledge recently but someone…who has lived it and worked through it down through the years,” CBC Chairman G K Butterfield told reporters on Thursday.
“We need a president who doesn’t simply campaign and just promise wonderful things, but things that are politically impossible to achieve,” he added.
Recognising the need to do more to court the black vote, Mr Sanders met civil rights leader the Reverend Al Sharpton in New York on Wednesday.
However, Mr Sharpton declined to say which candidate he would back after the meeting.
Mr Sanders acknowledged to US media on Wednesday that if the vote were held now in Nevada and South Carolina, he would likely lose.
“But I think we have momentum, I think we have a shot to win, and if we don’t win, we’ll do a lot better than people think we will,” he told the Washington Post.
In the last debate, Mrs Clinton sought to cast Mr Sanders as an idealist who would fail to get things done.
She has been sceptical his promises to reform Wall Street and the financing of political campaigns as well as his offers of universal healthcare and free university education.
But the former first lady faces challenges of her own, with questions continuing over her use of personal email during her term as secretary of state.
It is still unclear who the winner of the Democratic contest will face in the Republican race, with Donald Trump, John Kasich and Ted Cruz finishing in first, second and third in the New Hampshire primary.
Both Republican and Democratic parties will formally name their presidential candidates at conventions in July.
Americans will finally go to the polls to choose the new occupant of the White House in November.
Key dates to come
20 February – South Carolina primary (Republican); Nevada caucus (Democrat)
23 February – Nevada caucus (R)
27 February – South Carolina primary (D)
1 March – ‘Super Tuesday’ – 15 states or territories decide
18-21 July – Republican convention, nominee picked
25-28 July – Democratic convention, nominee picked
8 November – US presidential elections