On the 100th day, the president had fun. He zipped up to the nearest Rust Belt state full of the forgotten men and women who put him into office. He bashed the bad guys of the media and Hollywood and the swamp he’d just left behind. He promised jobs and greatness. It was like last year again, all lusty cheers and smiling faces, a refreshing tonic after three months of stubborn lawmakers, naysaying judges, carping protesters, frenetic days and lonely nights.

Donald Trump could have stayed home and had dinner with 2,700 card-carrying members of the Washington elite, many of whom make their living inspecting his every move for missteps, most of whom probably didn’t vote for him anyway. But he said no to the White House Correspondents’ Association dinner, where the swells in tuxedos and gowns feasted on jokes at his expense.

Instead, he spent Saturday night in Harrisburg, a town he’d described during the campaign as hollowed-out — “just rotting . . . It’s just a war zone.”

This time, he called it “a wonderful, beautiful” place. He soaked in the love of Harrisburg, people who’d waited in summer-strength sun for as long as 13 hours for the chance to tell their president they have his back.

From the top, Trump touted his decision to spurn the dinner in Washington and instead commune with his people in Pennsylvania. “A large group of Hollywood celebrities” — big boos — “and Washington media” — another wave of boos — “are consoling each other in a hotel ballroom,” he said. “I could not possibly be more thrilled than to be more than 100 miles away from Washington swamp . . . with much, much better people.”

(Alice Li,Jayne Orenstein,Julio Negron/The Washington Post)

Trump ran through a long list of actions he’s taken so far, and he defended some of his decisions to back away from campaign promises. It’s true, he said, that he hasn’t declared China a currency manipulator as he said he would, but “we have to have a little flexibility.” He said he’d asked China’s president to “help us out with North Korea,” and he couldn’t very well then say, “but by the way, you’re manipulating your currency. Doesn’t work that way. Do you agree?”

[After a tumultuous start, Trump hopes for a smoother agenda focused on jobs, taxes]

They did. They still believe he will “Make America Great Again,” and many in the crowd of about 7,000 people in an almost-full Farm Show Complex and Expo Center arena wore their red campaign caps to show it. They dressed to express their commitment, wearing shirts that said “Donald F---ing Trump” and “Deplorable Lives Matter” and “Trump — Finally Someone With Balls” and “Built Trump Tough.”

The man in that last tight black tee, Tony Kubin, 36, remembered that a year ago, “I was not into politics at all,” but then he heard Trump, and “everything he said, it was what me and my buddies have been saying forever. I mean, I hate political correctness.”

But now that Trump is president, Kubin is pleased that the president has altered his tone, become somewhat more presidential. “When he was running, it was refreshing because it was human, and that’s how people relate,” he said. “What he’s doing now, like putting off building the wall, that’s strategic. He’s learning that you can’t go in there and boom, boom, boom, get things done like a businessman would. Now he sees he has to work to bring everyone together. I know he’ll do that. I just love his honesty, how he says it’s harder than he expected.”

They’ve been watching Fox News and reading Facebook, and they’ve concluded that the Washington machine is blocking him at every turn. They blame the conservative Republicans, and they blame the Democrats, and they blame the news media, and they blame, even now, Hillary Clinton.

“Lock her up!” the crowd chanted spontaneously, again and again. They were families and young couples and old folks, lifelong Republicans and people who’d never voted for a Republican before, an almost entirely white audience, and they danced to Trump’s trademark soundtrack of ’60s and ’70s pop hits, and they chanted “Build that wall.”

“Don’t worry, we’re going to have the wall,” Trump assured the crowd. “Don’t even worry about it. . . . Rest assured. Go home, go to sleep.”

And they seemed okay with that. They want the wall, many people said. That’s foundational, basic, mandatory. But they don’t blame Trump for backing away from a threat to insist that funding for a wall be included in any agreement to keep the government functioning.

Becky Gee milked the cows just before midnight Friday night, and then she and her boyfriend piled into the truck and bombed down the highway, 4½ hours from their family farm in Hartville, Ohio, to the arena in Harrisburg, arriving just before the sun. “I came to hear him say how he’ll build the wall,” she said. “I know he will. I don’t feel he’s backing down, it’s just all these opposing forces that want to see him fail.”

She trusts Trump. She only wanted to hear him promise once again that he was really for people like her, people who work around the clock and still don’t know if there will be a market for their milk.

[From ‘build that wall’ to kick the can: Trump’s border promises might be hard to break]

Gee, 31, has heard the criticism about how the president’s staff members are consumed with infighting, about how Trump keeps reversing himself, about how he hasn’t gotten his initiatives through Congress.

“He’s being misinformed,” she said, “listening to the big companies and his advisers. He needs to meet with people like us so he can hear what we’re really going through. But I know he’ll do it. He gave up a millionaire’s lifestyle to do a job I wouldn’t do no matter what they paid.”

Trump said just what Gee was hoping for. He will build it. He will replace and repeal. He will destroy them. He could speak in shorthand here with his people. He didn’t need to answer pesky questions about whether he’d had to acknowledge complexity where he once saw black and white.

Here, he could exhale, presenting the nation’s challenges once more as a pretty easy fix, at least for him. Here — 120 miles from the canapés and cosmos at the Washington Hilton — he could once again be the plainspeaking provocateur who’d persuaded millions of Americans that he alone could turn the battleship. He could again become the voice of the collective id, kicking a-- and naming names.

“CNN and MSNBC are fake news,” he said. The news media “are a disgrace . . . incompetent, dishonest people.” “Senator Schumer,” he said, referring to the Senate minority leader from New York, “is a bad leader.” “Obamacare is dead, gone.” Transnational gangs such as MS-13 are “equivalent in their meanness to ­al-Qaeda.”

He returned to some of his campaign favorites — reading the poem “The Snake” (“Does anybody want to hear it again?” he said to resounding cheers), a parable about the dangers of inviting in a stranger whose bite turns out to be poisonous.

The crowd loved it. The president loved it.

[‘I was all set to terminate:’ Inside Trump’s sudden shift on NAFTA]

It’s not as if he doesn’t get out. There are the weekends at his Mar-a-Lago resort in Florida, plenty of golf and dinners at the steak places in his hotels. But this job has been more of a change than Trump, a 70-year-old man of routines, had anticipated. “I loved my previous life,” Trump told Reuters news agency this week. “This is more work than in my previous life. I thought it would be easier.”

He’s always loved work. But as he created and maintained the Trump empire, people mostly did what he told them to do. If he said it, he’d come to believe it was true.

This job is different. “Now arrives the hour of action,” he’d declared in his inaugural address. Then came week after week of what Washington does best: revision, reconsideration, realignment, rejection.

Trump responded as he always had in tough situations: He lashed out, called names, issued threats — and then he reversed course, backed down, changed the subject. He did it on Syria and on China, on immigration and on health care, on NATO and on the Export-Import Bank, on NAFTA and now even on the big Kahuna of Trumpian promises: the U.S.-Mexico border wall.

“I do change, and I am flexible, and I’m proud of that flexibility,” Trump said this month.

The people in the arena understood. “He’s relentless, unfaltering,” said Wes Black, 21, a student at Shippensburg University. “He’ll keep his promises. I don’t worry about him backing down on the wall. I’m most worried that Donald Trump eats his steaks extra well done and with ketchup. The rest, he can take care of.”

But as much as the crowd stood with their man, they, like the president, wouldn’t mind some wins. After all, he’d promised that there would be so much winning, Americans would be bored.

They’re not bored yet. “He’s learning as he goes,” said Lani Chong, 52, an auto inspector from State College, Pa. “He’s dialed back some of his tweets and antics, which I was never a fan of. I’d like to see the wall get built, but he has to get things approved. So he’s being flexible, which I like. I’m more of a centrist, and I took a chance on him because he’s a businessman. He’s not left or right, not really Republican even. I like that. I wish we had no parties — they just lock into left or right, and nothing gets done. He wants to fix stuff.”

The 100-day marker was just “ridiculous,” Trump tweeted, but he’d orchestrated a cavalcade of announcements, orders, signings and appearances designed to show that he had indeed delivered on some promises. His wins came with asterisks: His tax reform plan was only a rudimentary one-sheet outline. His immigration ban was quickly blocked by the courts.

But here, he was already a winner. He’d learned in the campaign that there was magic in big crowds, that he could read an arena as well as he could read a boardroom, that he could surf the waves of anger and joy as he reflected back to the masses their frustrations with the crooked path their lives had taken.

He loves the moment, and on this night, he was back in it. He told the crowd that next year, on the next Saturday night in April when the swells of Washington were toasting themselves, he might just come back to be with his people.

Mark Berman in Washington and Steve Volk in Harrisburg, Pa., contributed to this report.