TUCSON — Former president Barack Obama further sharpened his criticism of Donald Trump at a rally Friday, casting the Republican nominee as a huckster who lacks the mental fitness to lead the nation, leaning into a strategy of withering mockery as he hits the campaign trail in support of Vice President Kamala Harris.

With just over two weeks until Election Day, Obama spoke to a crowd the Harris campaign estimated at 7,000 people, who packed onto the turf field inside the University of Arizona’s football practice facility the night before the school’s hotly anticipated homecoming game. The Tucson rally was Obama’s first stop in a six-day, five-state whirlwind tour of the election’s fiercest battlegrounds.

The speaking spree underscores Obama’s evolving role in the presidential campaign’s waning days: from Harris’s trusted behind-the scenes sounding board and fundraising powerhouse, to a visible and vocal presence on the trail itself.

In his recent remarks — including Friday’s — Obama has assumed a distinct tone that few others could pull off, leaning on his experience, credibility and popularity, speaking in increasingly direct terms as he criticizes Trump and exhorts fellow Democrats.

“You would be worried if your grandpa was acting like this,” Obama said of Trump’s bizarre town hall appearance this week in which he stopped taking questions and instead swayed to music onstage for more than half an hour. “Tucson, we do not need to see what an older, loonier Donald Trump looks like with no guardrails.”

The speech continued Obama’s tactic of needling Trump where he’s most sensitive, an apparent effort to get under the Republican nominee’s skin and throw him off message. Obama’s prime-time address at the Democratic National Convention in August, for instance, was memorable for a suggestive barb about Trump’s obsession with “crowd sizes.”

In Arizona, Obama continued to workshop his critiques of Trump, sometimes assuming the tone of a stand-up comedian as he riffed on the Republican former president’s mental fitness and penchant for selling self-branded wares.

“When he’s not complaining, he’s trying to sell you stuff,” Obama said, grinning as the crowd laughed. “This is my favorite: He’s got the Trump Bible — wants you to buy the word of God, Donald Trump edition.”

Then Obama walked the crowd up to his real punchline: The Bibles, he noted, were printed in China.

“So, Mr. Tough Guy on China, except when he can make a few bucks hawking his Trump edition Bibles,” Obama said. “You can’t make this stuff up.”

Attendees embraced Obama’s new tone, with some saying it was refreshing to hear their side criticize Trump in a more direct, personal way.

“I’m enjoying that,” said Barbara Mosley, a retired teacher and Arizona native. “When he was president, he kind of held back, and you could tell. To me, I was like, ‘Why don’t you just spit it out?’ So I’m happy he’s doing that now.”

But Obama has also had some blunt words for voters, and he has caught some criticism for it. In Pittsburgh last week, Obama made headlines when he admonished Black men who were hesitant to vote for Harris because they “just aren’t feeling the idea of having a woman as president.”

For Marco Ruiz, a retired Tucson school administrator, the comments didn’t sit right. They felt too scolding, he said.

“I think his intent is always good, but I don’t really approve of that approach,” he said.

But his wife, Thelma Ruiz, had a different take: Tough but fair.

“If it’s going to get people off their couch, I think it’s great. I think they need it,” she said.

Before the Friday rally, Obama and Rep. Ruben Gallego, a Democrat who is running for U.S. Senate, met with a small group of male Latino voters, encouraging them to support Harris, who is trailing Trump in Arizona among young and middle-aged Latino men, according to a recent poll from USA Today and Suffolk University.

The meeting was private, and at the rally Obama opted for a more generalized and moderate version of the reproach, addressing any man who sees strength in Trump’s “bullying and putting people down.”

“I am here to tell you that’s not what real strength is,” Obama said, as he urged Arizonans to vote early.

The race in the state has tightened significantly since President Joe Biden dropped out in July, and The Washington Post’s polling average now shows Trump hanging onto a razor-thin lead. Biden won Arizona narrowly in 2020 and in 2022, a slate of Democrats prevailed in the contests for the state’s top offices.

This year, in addition to reprising its role as a key swing state, Arizona could also prove decisive in the battle for control of Congress. Gallego is running for Senate against Republican Kari Lake, who lost her gubernatorial bid two years ago, and there are several consequential House races throughout the state.

Voters also will decide whether to enshrine the right to an abortion in the state’s constitution, and Democrats hope that the issue will energize one of the country’s most purple electorates. Speaker after speaker at the Friday rally invoked reproductive rights and stressed that this year could be a historically close election.

“The issue of abortion access is very much on the ballot,” Kirsten Engel, a Democrat who is running to represent Arizona’s 6th Congressional District, said in an interview before the rally. “That is what I’m hearing at the doors I’m knocking on, women being very upset at their freedoms being taken away from them.”

The race for the southeast Arizona district — a rematch of 2022 — is especially competitive. “This is a battleground district in a battleground state,” Engel said.

Obama is the latest high-profile Democrat to visit Arizona, as the party puts on a full-court press with fewer than 20 days left in the race. Harris has stopped by twice in the past month, vice-presidential nominee Tim Walz was here last week and former president Bill Clinton — the last Democrat until Biden to win the state — is scheduled to visit Wednesday.

Trump and his running mate, JD Vance, have likewise made recent trips to the state and Vance is scheduled to return next week.

After Arizona, Obama is heading to Las Vegas on Saturday; Detroit and Madison, Wis., on Tuesday; and to Georgia on Thursday, where he’ll make his first joint appearance with Harris in a yet-to-be-announced city.

The two have been allies and friends for 20 years. In his August convention speech, Obama explicitly cast Harris as the successor in his political movement, saying then: “Now the torch has been passed.”

In 2008, Harris — then the district attorney in San Francisco — traveled to Iowa to knock on doors for Obama ahead of the state’s caucuses. Obama has been eager to return the favor.

His former aides have previously told The Post that he is relishing the rallies, which give him the chance to speak freely and act as an outlet for the anxiety he feels about the prospect of another Trump presidency.

On Friday, he appeared to be having fun. After some customary college football talk — “Don’t bet against the Wildcats tomorrow,” he said — Obama paused to clear his throat.

“You guys have to forgive me, because let’s face it, I’m a little out of practice,” he said with a smile. “But that’s okay, because what I have to say is going to make so much sense that even if I’m coughing a little bit, you’re still going to catch what I’m saying here.”