Michelle Obama laced into Donald Trump in an unsparing speech in Michigan on Saturday, accusing the former president of “gross incompetence” and “amoral character” while challenging Americans to choose Kamala Harris for US president.

“By every measure, she has demonstrated that she’s ready. The real question is, as a country, are we ready for this moment?” the former first lady told a rapt audience in Kalamazoo.

With the race virtually deadlocked, Obama said she was in battleground Michigan heeding her own advice to “do something”. In raw and strikingly personal terms, she asked why Harris was being held to a “higher standard” than her opponent. His handling of the Covid-19 pandemic and his efforts to cling to power after losing the 2020 election should be disqualifying, Obama argued, adding that Trump’s own former advisers and cabinet secretaries had stepped forward to warn against returning him to power.

“I hope you’ll forgive me if I’m a little frustrated that some of us are choosing to ignore Donald Trump’s gross incompetence while asking Kamala to dazzle us at every turn,” Obama said. “Preach!” a woman shouted.

The event in Kalamazoo, which Obama referred to as “Kamala-zoo”, was her first appearance on the campaign trail since her blockbuster speech at the Democratic national convention in August. Obama said voters shouldn’t choose Harris because she’s a woman but “because Kamala Harris is a grown-up – and Lord knows we need a grown-up in the White House”.

When Obama finished, Beyoncé’s Freedom blared and Harris emerged to thunderous applause. The two women hugged and walked together across the stage. When Harris spoke, she promised to be a president who listened to the American people, unlike her opponent, whom she accused of “looking in the mirror all the time”.

“Just imagine the Oval Office in three months,” she said. “It is either Donald Trump in there stewing over his enemies’ list – or me working for you, checking off my to-do list.”

Before the event, Harris visited a local doctor’s office in nearby Portage, where she spoke to healthcare providers and medical students about the impact of abortion restrictions. Harris has made protecting what remains of abortion access a major theme of her closing argument to voters, using it to draw a sharp contrast with Trump, who has claimed credit for his role in overturning Roe v Wade but insisted he would allow a nationwide ban as president.

In Kalamazoo, both Harris and Obama argued that Trump had no credibility on the matter. But Obama went further, describing the full spectrum of women’s reproductive health – from period cramps to pregnancy to menopause. She lamented the lack of research on women’s health and the racial disparities in treatment. Directing her comments to the “men who love us”, Obama asked them to consider the harm that is done when a government “keeps revoking the basic care from its women”.

“I am asking y’all, from the core of my being, to take our lives seriously,” she said, her voice swelling with emotion. “If we don’t get this election right, your wife, your daughter, your mother, we as women will become collateral damage to your rage.”

Abortion bans, she argued, affected men as well. If something happened during a pregnancy or a delivery and the doctor was prevented from providing care, “you will be the one praying that it’s not too late. You will be the one pleading for somebody, anybody, to do something, and then there is the tragic but very real possibility that in the worst-case scenario, you just might be the one holding flowers at the funeral,” she said.

Obama seemed to be speaking of the gaping gender divide that has emerged in this race, with women powering Harris and men turning to Trump. She acknowledged the country had a long way to go, and that change was too slow, but she said sitting out or voting third-party would not move the country forward.

While Barack Obama is known as his party’s great orator, Michelle Obama remains one of its most popular albeit reluctant speakers. Having once encouraged Democrats to “go high” when they “go low”, Obama on Saturday made no effort to conceal her disdain for the man who led a years-long campaign questioning her husband’s birthplace.

“In any other profession or arena, Trump’s criminal track record and amoral character would be embarrassing, shameful and disqualifying,” she said.

The Harris campaign deployed Obama – along with Barack Obama and other leading figures and celebrities – in hopes their star power might add an 11th-hour jolt to a presidential race that has been otherwise static.

Harris and Trump were both in Michigan on Saturday, chasing the state’s 15 electoral votes. After Pennsylvania, where Harris will campaign on Sunday, Michigan is perhaps the next most critical state on the Democrat’s path to the White House.

Trump won the state in 2016, when he tore down the trio of “blue wall” states. But four years later, Michigan delivered Biden his biggest swing state victory and Democrats swept the state in the 2022 congressional midterms, after the supreme court ruling overturning Roe v Wade.

Polls show a dead heat. Trump has sought to exacerbate Democratic divisions over the Biden administration’s handling of Israel’s war in Gaza and Lebanon, elevating the issue in Michigan, where scores of Muslim and Arab American voters have said they cannot support Harris. On Saturday, Trump was joined on stage in Novi, Michigan, by Bill Bazzi, the current and first Muslim mayor of Dearborn Heights.

“I have never seen the devastation that we’re seeing right now,” Bazzi said. “When President Trump was president, there was no wars.”

The Harris campaign has conducted several outreach attempts to the Arab community, but tensions remain high with little time for a course change and the risk of escalation following Israel’s pre-dawn strikes on Iran. At the event, Harris was interrupted by a pro-Palestinian protester. “We have to end that war,” she responded, as the crowd drowned out the demonstration with “Kamala” chants.

Democrats are focused on juicing turnout in Detroit – which Trump insulted (again) at his Novi event on Saturday – while aggressively courting women, independents and anti-Trump Republicans in the suburbs. Her campaign recently earned the support of Fred Upton, the state’s long-serving Republican representative who left office in 2022. Upton told the Detroit Free Press that he had never supported a Democrat for president but this year cast an absentee ballot for Harris: “He’s just totally unhinged. We don’t need this chaos.”

Speaking before Harris, Michigan senator Gary Peters compared the presidential campaign to the highest-stakes job interview. Extending the metaphor, he suggested that they check Trump’s references. The senator quoted Trump’s former chief of staff John Kelly, who recently said on the record that his former boss fit the definition of a fascist.

“Would you hire that guy?” Peters asked. “No!” the crowd thundered back.