At the end of the most tumultuous week of the Republican presidential campaign, one that threatened to upend his march to the nomination, Mitt Romney found order in a simple chore.

The South Carolina polls would close in a few hours, yet here was the central-casting candidate, a polished patrician worth upward of $200 million, feeding quarters into a laundry machine. His wife, Ann, comfy in a yellow sweatshirt, kept him company as they sat alone in the Columbia Marriott’s guest laundry room listening to the dryer churn.

When a reporter stumbled upon them, Romney was relaxed, even whimsical, fretting over a sock that fell between the machines and extolling the virtues of Brooks Brothers non-iron dress shirts.

This was a far cry from the thrown-off-balance Romney, stammering on the debate stage trying to talk about his taxes and wealth. Or from the suddenly humbled Romney, reaching for excuses to explain why one rally crowd was so meager — “Gosh, this is a workday, right?” Or from the fight-to-win Romney, coming alive with fiery rhetoric and stirring an impassioned crowd Friday night in Greenville, S.C.

Which of these will Romney be going forward?

Apparently the latter.

In conceding defeat here Saturday night, Romney was a stoic warrior. He’s a competitive creature, and those instincts kicked in as he girded supporters for a long battle with a resurgent Newt Gingrich.

There were notes of humility, but not defiance. Instead, he was upbeat and passionate, saying he will “keep fighting for every single vote . . . in every single state” as he put in sharp focus the party’s choice between himself and the former House speaker.

“I don’t shrink from competition; I embrace it,” Romney told supporters. “I believe competition makes us all better. I know it’s making our campaign stronger. And in the coming weeks, the ideals of free enterprise and economic freedom will need a very strong defense, and I intend to make it.”

Mitt Romney is a man of order. All his life, he has had a plan, and he executes his missions accordingly. But his plan to polish off his rivals in South Carolina flew out the window this week.

How Romney deals with his new adversity will say a lot about what kind of man he is and what kind of president he may be. And after South Carolina, he has just 48 hours before stepping back onto the debate podium Monday night in Tampa.

He could be scrappy and passionate — something South Carolina voters said they wanted — as he was Friday night after a week of getting pummeled. By the time he reached Greenville for the 9 p.m. rally, he looked exhausted. His loafers were still damp from standing in a pouring rain to give a stump speech that morning.

Yet as soon as Romney grabbed the microphone, he seemed to transform into a different candidate. He seemed to speak from the heart — however rehearsed he may have been — telling zany new jokes and delivering tough new lines about President Obama.

On the stump, Romney likes to draw a contrast between the palatial offices of executives at Solyndra, a failed solar-energy company whose loans were backed by the Obama administration, and Staples, the office-supply company Romney helped launch on the cheap.

Romney talks about the Naugahyde chairs Staples used at its headquarters. But this time, he added a fresh quip: “Killed a lot of Naugas to get these babies!”

Romney is not a candidate used to being interrupted by cheers, but his overflow crowd of more than 400 ate his shtick up.

“We need Mitt! We need Mitt! We need Mitt!” they chanted.

“You know what?” he replied. “You’re gonna get me.”

“You guys in Greenville,” Romney added, “this is the best audience I’ve been to in a long time.”

Or ever.

It was difficult to recall a campaign event this past year where the former Massachusetts governor has made such an electric connection with his audience. To be sure, Romney had some reinforcements in two of the Republican Party’s star governors — South Carolina’s Nikki Haley and Virginia’s Robert F. McDonnell — who introduced him.

Still, it was Romney whom voters in the crowd said they marveled at. The man in person, some said in interviews after the rally, was nothing like the stiff, scripted and humorless politician they have come to know through more than a dozen debates.

“I happen to believe that I’m the only guy in this race who can beat Barack Obama,” Romney said, drawing loud applause from the crowd.

“I think you have to have someone who’s had experience in the private sector, who knows how the economy works, who can bring that experience to post up against Barack Obama, a different background, different experiences, can stand up to him and say, ‘You know what? Your stimulus did not work, Mr. Obama,’ ” Romney continued.

After exhorting his captive audience to “get the job done,” Romney tossed his microphone back to Ann and dived into the crowd.

The next afternoon, there Romney was in the laundry room, as if he didn’t have a worry in the world. He still had on the windowpane shirt and Gap jeans he wore that morning to Tommy’s Country Ham House, where an anticipated showdown with Gingrich never came to be.

About an hour later, he darted through the Marriott lobby, carrying a plastic bag of clean clothes. “Got my darks!” he told a reporter.

As he rode the elevator with Ann up to their room, Romney was planning ahead.

“We’re on to Florida and Nevada,” the candidate said. “And where else?”