US Vice President Kamala Harris visited a Detroit art gallery on Tuesday accompanied by three Hollywood stars for a conversation with black men about entrepreneurship as both she and Donald Trump sought to energise key constituencies their allies worry may be slipping away.

Ms Harris was joined by Don Cheadle, Delroy Lindo and Cornelius Smith Jr at the Norwest Art Gallery.

Ms Harris singled out London-born Lindo, who has starred in a number of Spike Lee films and CBS’s The Good Fight, saying to the gathered crowd: “Delroy has been supporting me for years and years and years,” and adding that the two were both on the debate team at her alma mater, Howard University.

Ms Harris reminded the group that early voting starts in Michigan in four days. Mr Trump, meanwhile, focused on reaching women. He planned to tape a Fox News Channel town hall featuring an all-female audience and moderated by host Harris Faulkner.

Kamala Harris poses for a photo
Democratic presidential nominee Vice President Kamala Harris poses for a photo as she visits Norwest Gallery of Art in Detroit (Jacquelyn Martin/AP)

Ms Harris’s running mate, Minnesota Governor Tim Walz, unveiled his ticket’s plan to improve the lives of rural Americans. It was yet another sign that in a razor-tight race, each side is trying to cut into the other’s margin of support with different voting blocs while shoring up traditional areas of strength.

Ms Harris, too, will appear at a town hall-style event in Detroit hosted by the morning radio programme The Breakfast Club, featuring Charlamagne Tha God, who is especially popular with black males.

The push comes a day after she announced a series of new proposals dubbed the Opportunity Agenda for Black Men. The ideas are meant to offer the demographic more economic advantages, including providing forgivable business loans of up to 20,000 dollars (£15,273) for entrepreneurs and creating more apprenticeships. The plan would also support the study of sickle cell and other diseases more common in black men.

The focus on black men sharpened last week when former president Barack Obama campaigned for Ms Harris in Pittsburgh and said he wanted to speak “some truths” to black male voters, suggesting some “just aren’t feeling the idea of having a woman as president”.

The vice president’s campaign says it doesn’t believe black men will flip in large numbers to supporting Mr Trump, especially after strongly backing Democrat Joe Biden, with Ms Harris as his running mate, in 2020. They are more concerned about a measurable percentage of black males opting not to vote at all.

Senator Raphael Warnock, the first black senator elected from the state of Georgia, issued a stark warning in Atlanta to other black men that voting for Mr Trump will be “literally dangerous” for them, as the former president heads there for a rally.

“He will be dangerous every time you get in the car and you deal with the issue of driving while black,” Mr Warnock said.

He argued that Democrats’ job is to reach black men who are deciding whether to vote at all.

“The issue is folks have got to understand that if you do not vote, it’s a vote for Donald Trump,” Mr Warnock said.

Ms Harris’s campaign has also placed special emphasis on other male voters, including creating Hombres con Harris, or Men with Harris, a group that is using celebrities and key elected officials to organise events on her behalf meant to appeal to Hispanic men.

As she campaigns in Detroit, Harris faces other potential challenges in Michigan, including Arab activists angered by the Biden administration’s full-throated support for Israel in its war with Hamas in Gaza. Dearborn, outside Detroit, is the largest Arab-majority city in the US.

Mr Trump is scheduled to return to Detroit later this week for a rally.

Donald Trump speaks during an interview with Bloomberg News editor-in-chief John Micklethwait
Republican presidential nominee Donald Trump speaks during an interview with Bloomberg News editor-in-chief John Micklethwait during an event with the Economic Club of Chicago on Tuesday (Evan Vucci/AP)

Still, the vice president’s campaign expects to see strong support on election day from white, college-educated voters in Michigan at rates that might exceed Mr Biden’s in 2020, and she hopes to expand the margin by which Mr Trump lost many of the state’s key suburbs four years ago.

She has also seized on insults Mr Trump made about Detroit last week while campaigning there. He said if Ms Harris wins “our whole country will end up being like Detroit”. He added: “You’re going to have a mess on your hands.”

The former president expects to do well with rural voters, but team Harris hopes to at least keep things closer. And while Ms Harris’s support among women is strong, Mr Trump aims to keep her from running up the score.

Mr Trump has seen his support among women, especially in the suburbs of many key swing states, soften since his term in the White House. A September AP-NORC poll found more than half of registered voters who are women have a somewhat or very favourable view of Ms Harris, while only about one-third have a favorable view of Mr Trump.

To reverse the trend, Trump has sought to cast himself as being able to personally shield women from various threats, as when he suggested at a rally in Pennsylvania last month that women in America, “will no longer be abandoned, lonely or scared. You will no longer be in danger”.

“You will be protected, and I will be your protector,” Mr Trump said then. He has also suggested that, should he win, women will no longer have a reason to think about abortion, after three Supreme Court judges that he appointed helped in 2022 to overturn the landmark Roe v Wade decision that had guaranteed a woman’s right to the procedure.

In Chicago before members of the Economic Club, Mr Trump defended his support for high tariffs as an economic cure-all.

“To me, the most beautiful word in the dictionary is ‘tariff’,” Mr Trump told Bloomberg editor-in-chief John Micklethwait, who interviewed him at the event.

Mr Micklethwait has repeatedly pressed Mr Trump on warnings from economists that the costs of high tariffs will be passed along to American consumers, raising prices.