He advanced his takeover of the Republican Party. He proved that he can dominate a race in the Deep South. He vanquished the dynasty that ruled the GOP establishment for decades as Jeb Bush dropped his White House bid.
And in the process, Trump left no doubt that he is the GOP's national front-runner and has the most credible path to capture the party's nomination.
In Nevada's Democratic caucuses, meanwhile, Hillary Clinton deployed an intricately built organizational machine to register a much needed and stabilizing victory over Vermont Sen. Bernie Sanders, slowing her rival's surge following his stunning rout in the New Hampshire primary.
Her victory, and the looming Democratic South Carolina primary next week in which she is a favorite, doesn't mean the end for the more liberal Sanders, against whom she seems fated to fight in long war of attrition. But it was Clinton's best night for weeks in a crisis-scarred campaign and indicated her firewall of minority voters is still intact and raises the chances that she will eventually claim the nomination — and head on to a possible battle for the ages between her own establishment political dynasty and Trump.
At 11:30 p.m. ET with 99% of the vote counted in the Republican primary, Trump was in the lead at 32.5%, with Florida Sen. Marco Rubio and Texas Sen. Ted Cruz in an effective tie on 22.5% and 22.3% respectively. Bush trailed in fourth at 7.9% just ahead of Ohio Gov. John Kasich and former neurosurgeon Ben Carson.
On the Democratic side, with 88% of the vote counted, Clinton held an unassailable lead with 52.6% compared to 47.4% for Sanders.
Of course, both parties have awarded only a small portion of the delegates that will ultimately be needed to clinch the nomination.
But as he addressed supporters on Saturday night, Trump seemed to appreciate something had changed.
"Let's put this thing away," Trump roared.
For so much of the wild 2016 campaign, the conventional wisdom suggested that Trump, running a campaign based on insults, vague vows to Make America Great Again and laboring under a questionable conservative pedigree, will fade.
But after his two massive primary wins, that's no longer the case.
South Carolina, after all, has long prided itself on picking Republican nominees. It has handed victory to the eventual Republican standard bearer every cycle since 1980 -- with the exception of Newt Gingrich in 2012.
And Trump can now bask in the fact that every Republican who has won both New Hampshire and South Carolina has gone on to claim the nomination.
His victory Saturday night came with huge symbolic overtones. The state's collection of national security conservatives, evangelicals, tea party voters and more moderate establishment conservatives offers a fair microcosm of the GOP itself.
Trump now looks even more formidable as he enters the 13 Super Tuesday states — once he has navigated the Nevada GOP caucuses Tuesday — with contests looming in places like Alabama, Arkansas, Georgia and Texas where he polls consistently well.
And there was more proof that Trump's bare-knuckle, profane and scorched earth campaign style cannot hurt him -- in fact, it's drawing supporters to him.
After all, in South Carolina, Trump shattered GOP taboos by accusing the last Republican President, George W. Bush, of lying to the public about the Iraq War and failing to prevent the September 11, 2001, attacks.
He also feuded openly with Pope Francis and cited an apocryphal story about a U.S. general who purportedly dipped bullets in pigs' blood to execute Muslim prisoners a century ago in an effort to deter Islamic terrorism.
It made no difference. Trump converted his poll numbers to a 10-point primary victory, suggesting that he may be even more impervious to damaging his own fortunes than the Teflon president himself, Ronald Reagan.
He summed up his own hardball campaign strategy as he addressed his supporters, reflecting that even for someone who styles himself as the ultimate tough guy, running for president is a hard business.
"It's tough, it's nasty, it's mean, it's vicious, it's beautiful. When you win, it's beautiful," Trump said Saturday night as he declared victory.
Another factor in Trump's favor: The opposition to him remains split. The bitter fracas between Rubio and Cruz ended with each of the young pretenders to the next generation of conservative leadership taking nearly a quarter of the electorate.
That means there is little incentive for either to drop out even though they are splitting the conservative vote.
Cruz billed himself as the only true conservative left in the race.
"We are the only campaign that has beaten, and can beat, Donald Trump," he said.
Rubio celebrates a comeback
A jubilant Rubio bounced back after his disastrous performance in New Hampshire to proclaim that the GOP race was now a three-man affair. His campaign expects to pick up disenfranchised Bush supporters and believes it will now start to emerge as the only genuine alternative to Trump.
"If it is God's will that I should serve as the 45th president ... history will say that on this night in South Carolina, we took the first step forward in the beginning of a new American century," Rubio said, delivering what amounted to a victory speech despite finishing well behind Trump — just as he had after his third-place spot in the Iowa caucuses.
But though Cruz won Iowa and Rubio appears to have the kind of crossover appeal that could unite several blocs of the Republican Party, it was still unclear where exactly the two Cuban-American senators can stop Trump.
It turns out, meanwhile, that former first lady Barbara Bush had it right many months ago, when she said in an unguarded moment: "We've had enough Bushes."
Though she eventually came around to her son's campaign and was on the stump with him in its twilight, Jeb Bush's mother had put her finger on the fierce anti-establishment mood that was not then evident but would shape the 2016 race.
With his tearful wife Columba — who had never wanted her husband to run — at his side, Bush's political career came to an end in a state that had resurrected the hopes of his father and brother in their presidential campaigns.
But he did not leave without a repudiation of the kind of politics that Trump has introduced into the Republican Party and which is so alien from that practiced by his own family for decades.
"Despite what you might have heard, ideas matter, policy matters," Bush said in making a clear implicit case that Trump was not qualified to be president.
"I firmly believe the American people must entrust this office to someone who understands that whoever holds it is a servant, not the master, someone who will commit to that service with honor and decency."
But after Saturday night, Bush-style politics is in the past. And the future may belong to Trump.