Donald Trump has won the South Carolina primary, putting him in a commanding position in the Republican nomination fight.

The New York businessman, whose candidacy was initially dismissed as a joke when he announced last summer, has now won the first two GOP primaries after placing second in the Iowa caucuses. No Republican candidate who has won both New Hampshire and South Carolina has ever lost the nomination.

"It's an incredible movement with incredible people," a triumphant Trump declared a rally in South Carolina in supporters, looking ahead to future primaries and saying, "Let's put this thing away."

The remaing question is whether he'll encounter trouble ahead as the field narrows and his past positions gain more scrutiny. On Saturday night, former Florida Gov. Jeb Bush, a frequent punching bag for Trump, had already announced he was dropping out of the race after a poor showing.

In a victory speech, Trump dismissed concerns that he would have trouble as the field narrows. "As people drop out, I'm gonna get a lot of those votes also," he predicted.

As Trump did his victory lap, Sens. Ted Cruz and Marco Rubio were locked in a battle for second, with Bush, Gov. John Kasich and Ben Carson well behind.

Campaigning for president in the conservative and evangelical state, Trump challenged the orthodoxy. He came under fire from Iowa winner Cruz for having taken liberal positions at various times on abortion, healthcare and gun rights. In a turbulent performance in the final GOP debate before the first-in-the-South primary, Trump said that President Bush lied the nation into the war in Iraq. He also argued, in a bitter exchange with rival Jeb Bush, that the former president didn't keep the country safe, because Sept. 11 happened on his watch. Trump even found himself in a war of words with Pope Francis in the 48 hours before the primary.

As the brash businessman has so often proved, moments that would have destroyed the candidacies of his rivals have intensified the loyalty among Trump supporters. With the help of social media and an ability to dominate headlines, Trump rode his message — of cracking down on illegal immigration, dealing more aggressively on trade deals with China, and using his business savvy to restore American greatness — to victory. In the end, he staved off Cruz and a late surging Rubio.

Trump will now enjoy tailwinds as the race moves west to Nevada, where he's polling above 40 percent and owns a Las Vegas casino that towers over the state's most populated city.

On Sunday, Trump will hold a rally in Atlanta, Ga., before traveling to Nevada for his final campaign ahead of the state's Feb. 23 Republican caucuses.

On March 1, just a week after Nevada, 11 states hold primaries on a single day, meaning that there will be a race to claim the title of "anti-Trump," because unless his opponents rally around an alternative, he could rack up enough victories that his momentum would be irreversible. Cruz and Rubio will be vying for that position and that could play into the hands of Trump.

Ahead of his victory Saturday night, the billionaire predicted that a win in South Carolina could hand him his path to the nomination at the Republican National Convention in July.

"If we win in South Carolina, we feel we could run the table," Trump told a roomful of supporters in Walterboro, S.C., earlier this week.