Hillary Clinton concedes she has work to do despite Nevada win
Hillary Clinton admitted she has work to do to convince voters she has their best interests at heart, even as she celebrated her weekend win over rival Democratic presidential candidate Bernie Sanders in Nevada.
On the Republican side, senators Marco Rubio and Ted Cruz fought to emerge as the true anti-Donald Trump candidate after the billionaire businessman's resounding victory in South Carolina established him as the party's clear frontrunner.
Mrs Clinton was happy with her Nevada win but conceded that some voters are sceptical of her motivations.
The former US secretary of state said on CNN: "I think there's an underlying question that maybe is really in the back of people's minds and that is, you know, is she in it for us or is she in it for herself?
"I think that is a question that people are trying to sort through."
A large majority of black voters supported Mrs Clinton in Nevada, according to polls, an outcome that bodes well for her in next Saturday's Democratic primary in South Carolina.
It is also a good omen for so-called Super Tuesday a few days later when primaries are held in several southern states where African-Americans make up a large segment of the Democratic electorate.
Working to increase his support among black voters, Mr Sanders visited a Baptist church lunch following services in West Columbia, South Carolina, and talked up the country's economic recovery under President Barack Obama.
Mr Sanders, a Vermont senator, acknowledged that while his insurgent campaign has made strides "at the end of the day ... you need delegates".
He listed Colorado, Minnesota, Massachusetts and Oklahoma as places where he has a "good shot" to do well on March 1, or Super Tuesday, which offers a large haul of delegates who will choose the party's nominee at the national convention in July.
As for Mr Trump, he declined to say the Republican nomination was his to lose, but he quickly went on to declare: "I'm really on my way."
Complete but unofficial returns in South Carolina put Mr Trump way out ahead, with Mr Rubio squeaking past Mr Cruz for second.
But with roughly 70% of Republicans in national polls declining to back Mr Trump, Mr Cruz and Mr Rubio tried to cast themselves as the one candidate around whom what Mr Rubio calls the "alternative-to-Donald-Trump vote" can coalesce.
Mr Rubio also accused Mr Trump of a lack of specifics on policy.
"If you're running for president of the United States, you can't just tell people you're going to make America great again," he said, referring to Mr Trump's campaign slogan.
Mr Rubio took note of the smaller Republican field after former Florida governor Jeb Bush's departure from the race.
He suggested it was only a matter of time before John Kasich and retired neurosurgeon Ben Carson ended their campaigns as well.