He urged the audience of college students not to think they were too young to accomplish great things, before waxing on about tariffs. “Don’t try to be someone else,” he implored them, after attacking due process for unauthorized immigrants. And he told them not to think of themselves as victims, before diverting into how the 2020 election was “rigged” against him.

On Thursday night, President Trump addressed the 2025 graduates of the University of Alabama, vacillating between campaign rally material and a commencement speech as he used his past political grievances to encourage students to fight for their futures.

Addressing the students at Coleman Coliseum in Tuscaloosa, flanked by signs that read “The American Dream Is Back,” Mr. Trump told students they were “the first graduating class of the golden age of America,” and used his comeback story to encourage the students to trust their instincts and be ambitious as they navigate the world.

“In recent years, too many of our young people have really been taught to think of themselves as victims, and blame people, and be angry,” he said. “But in America, we reject that idea that anyone is born a victim. Our heroes are the ones who take charge of their own destiny, make their own luck and determine their own fate, despite the odds.”

At points in the address, the president rattled off familiar advice for college graduates. But Mr. Trump — who acknowledged that he did not use his teleprompter for much of the speech — veered off into various rants that echoed the blitz of political appearances he has put in this week to celebrate his 100th day in office. The largely receptive crowd often cheered at the scattershot injection of issues from the price of eggs to transgender rights, a microcosm of an era when even the pablum of a graduation speech cannot escape the politics of the moment.

Some of Mr. Trump’s stories focused on how he himself had been victimized throughout his political career, from being counted out by other politicians who never thought he could become president to potentially facing down another impeachment.

He also reveled in his victories, recounting his election results, including his commanding victory in Alabama, which he said felt like “home” when he was starting out as a candidate in 2015. A big rally he held in the state was among the first signs that Mr. Trump might have something beyond coastal appeal.

“So never let anyone tell you that something is impossible,” he said. “Ever, ever, ever. In America, the impossible is what we all do best. There’s nothing you cannot do if you’re willing to fight for it.”

“Fight, fight, fight,” he added, invoking a slogan spurred by a failed assassination attempt on him on the campaign trail last year.

Mr. Trump told the graduates that they had to “break the system a little bit and follow your own instincts,” seemingly describing his breakneck, flood-the zone strategy that has plunged the federal government into chaos and the country to the brink of a constitutional crisis.

“Change is never easy, and the closer you get to success, the more ferociously those who have a vested interest in the past will resist you,” he said.

Mr. Trump also gloated about how he faced far less resistance in his second term, citing “internet people” and others who now bow down to him. “They all hated me in my first term,” he said, adding with an expletive that they were now kissing up to him.

Even in a college town, Mr. Trump was in relatively friendly territory in the heavily Republican state, which he carried easily in all three of his presidential bids. But there were protests, and a petition from the University of Alabama Democrats and the local chapter of the N.A.A.C.P. against Mr. Trump’s appearance drew more than 26,000 signatures.

“Americans are once again waking up to the fact that this wannabe monarch wants to rule over us like a king,” Braden Vick, the president of the University of Alabama Democrats, said in a statement announcing the protest.

About two miles from Coleman Coliseum, the university’s Democrats held a protest joined by former Representative Beto O’Rourke of Texas and former Senator Doug Jones of Alabama.

“We’ve got to show up to where the fight is, and that includes places like Alabama, which has just been written off by the Democratic Party for far too long,” Mr. O’Rourke said in an interview after the protest. “And the message was: The people have the power. And when folks show up, as they did at the protest today or the marches or these no-show town halls, it really begins to move the rest of the country.”

Benard Simelton, the president of Alabama’s N.A.A.C.P., compared Mr. Trump to the state’s former governor, George Wallace, who built his political career as a populist and segregationist.

“He is the president of all people, and yet he has failed every citizen miserably with his divisive, destructive policies, while inflicting horror on our Hispanic, Latino and other communities,” he said in a statement opposing his visit. “Wallace’s infamous words can still be heard today, ‘Segregation today, segregation tomorrow, and segregation forever.’”

But Mr. Trump was enthusiastically received by the thousands of attendees at Coleman Coliseum. Mr. Trump’s address was part of a “special ceremony” before 6,000 students begin attending formal graduation ceremonies on Friday. The pre-commencement ceremony was optional for students, and tickets were opened to guests.

Despite Mr. Trump’s falling approval ratings, the commencement offered a window into the resilience of much of his support outside Washington, and a gauge on the culture shift in the country that got him elected.

There were at least as many red “Make America Great Again” hats in the crowd as there were special red graduation hats signifying a graduate’s 4.0 grade point average. The crowd broke into chants of “U.S.A.,” reveled in Mr. Trump’s extensive praise of its sports teams and roared when he talked about the “clean shores of the Gulf of America.” They cheered when he talked about keeping transgender women from playing on women’s sports teams, and some laughed when Mr. Trump spent several minutes mocking matchups that involve transgender players.

Mr. Trump’s warm reception came as he is waging an assault on the higher education system. While the administration so far has taken aim largely at the nation’s most elite colleges, the University of Alabama has not been spared.

Last month, a doctoral student at the University of Alabama was detained by federal immigration authorities, amid the administration’s campaign to deport noncitizen college students for engaging in forms of protest. Alireza Doroudi, an Iranian citizen, was legally in the United States and detained in Louisiana.

Mr. Trump used the address to take shots at Harvard, which has stood up to him in the administration’s effort to overhaul institutions it sees as too liberal and powerful. Mr. Trump bragged that his administration is withholding billions from Harvard, and pitted the two universities against each other — as if forecasting a battle.

“It is clear to see the next chapter of the American story will not be written by the Harvard Crimson,” he said. “It will be written by you, the Crimson Tide.”