REUTERS - Republican presidential candidate Donald Trump rolled to victory on Saturday in South Carolina in a contest that saw former Florida Governor Jeb Bush drop out.

The victory by Trump, who is running as an anti-establishment outsider, solidified his position as the front-runner to win his party's nomination ahead of the November 8 presidential election.

S. Carolina primary: Trump's victory speech, Bush's resignation and Rubio's

The night's most prominent casualty, Bush suffered a distant fourth place finish in the Republican contest and announced he had suspended his campaign, ending his dream of becoming a third Bush president after his father and brother.

"The people of Iowa, New Hampshire and South Carolina have spoken, and I really respect their decision," an emotional Bush said in Columbia. He finished far out of the running in each of the first three states.

By winning both South Carolina and New Hampshire and holding leads in 13 states that hold Republican contests on March 1, Trump was arguably on track to win the nomination, an outcome that seemed astounding to contemplate when he entered the race last summer.

"It's going to be very difficult for him to be derailed at this point," said Hogan Gidley, who was a senior adviser to former Republican candidate Mike Huckabee.

The 69-year-old real estate billionaire and reality TV star was declared the winner in South Carolina about an hour after polls closed, and launched into a feisty victory speech.

"Let's put this thing away," Trump told cheering supporters in Spartanburg.

He denounced TV pundits for saying there could be enough anti-Trump votes to beat him when the race thins further.

"These geniuses," he said. "They don't understand that as people drop out, I'm going to get a lot of those votes also. You don't just add them together."

Trump easily defeated Florida Senator Marco Rubio and Texas Senator Ted Cruz, who were in a close fight for second place and the right to declare themselves the anti-Trump alternative.

With 99 percent of South Carolina precincts reporting, Trump had 32.5 percent, followed by Rubio with 22.5 percent and Cruz with 22.3 percent.

Cruz's inability to distinguish himself from Rubio in the state was a blow to his campaign, which had invested heavily there to rally support among South Carolina's large population of evangelical voters.

Trump's victory won him at least 44 of the state's 50 delegates, bringing his delegate count to 61, compared to 11 for Cruz and 10 for Rubio, according to a tally by Real Clear Politics. Republicans need 1,237 delegates to win the party nomination.

It was Trump's second victory in a row, an outcome that frightens establishment Republicans but thrills the "throw-the-bums-out" conservative base of the party that has long been fed up with Washington.

Trump, who has also advocated a ban on Muslim immigrants to counter domestic terror threats, stirred fresh controversy on Friday when he told a crowd about a U.S. general who was said to have dipped bullets in pigs' blood to kill Muslim prisoners a century ago.