Republican presidential hopeful Donald Trump has won the South Carolina primary, cementing his status as the man to beat for GOP’s nomination.

In the Democratic contest, Hillary Clinton beat Vermont Senator Bernie Sanders in a tight race in Nevada.

Both results will be key ahead of the “Super Tuesday” round on March 1, when a dozen more states make their choice.

Donald Trump’s victory claimed a major scalp when former Florida Governor Jeb Bush dropped out of the race.

Jeb Bush finished a distant fourth, days after his brother, former President George W. Bush, made a rare political appearance to boost his flagging campaign.

Republican senators Ted Cruz and Marco Rubio were locked in a battle for second place in the state.

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“There’s nothing easy about running for president,” Donald Trump said at his victory rally in Spartanburg on Saturday evening.

“It’s tough, it’s nasty, it’s mean, it’s vicious. It’s beautiful – when you win it’s beautiful.”

Donald Trump’s supporters erupted at his campaign headquarters when the projected results were announced.

His campaign has been dogged in controversy, with his latest spat with Pope Francis on Christian values hitting the headlines this week.

Thousands of miles west, Hillary Clinton narrowly beat Bernie Sanders, who had beaten her convincingly in New Hampshire in their last contest.

“Some may have doubted us, but we never doubted each other,” Hillary Clinton told supporters at a victory rally in Las Vegas.

“This is your campaign.”

The battle between them has grown increasingly close in recent weeks, with Hillary Clinton expected to win Nevada in double digits just weeks ago.

However, Ted Cruz, who has successfully galvanized young voters with his calls for free university education, appears to have performed better than expected among Hispanics in Nevada.

According to NBC exit polls, Bernie Sanders won among Hispanics with 53% of the vote but lost among black voters earning just 22% of their vote.

Hillary Clinton’s next test will be in the Democrats’ South Carolina primary on February 27. Republicans will hold their own caucuses in Nevada on February 23.

Once each state has voted in the primaries or caucuses, the delegates won by each party candidate will go on to endorse them at party conventions in July.