Former President Barack Obama on Thursday admonished Black men who are hesitating to back Vice President Kamala Harris’ presidential campaign, telling them it’s “not acceptable” to sit out this election and suggesting they might be reluctant to vote for Harris because she’s a woman.

The striking comments by Obama, made to a small group of voters in a surprise stop at a local Harris campaign office in Pittsburgh, were part of a more forceful campaign message delivered by the former president on Thursday as polls continue to show a neck-and-neck race. At a rally in the city later that evening, Obama issued some of his most searing public criticisms of his successor to date.

The lack of energy some see around Harris’ campaign, Obama first told the smaller group, “seems to be more pronounced with the brothers.”

“You’re thinking about sitting out or supporting somebody (in former president Donald Trump) who has a history of denigrating you, because you think that’s a sign of strength, because that’s what being a man is? Putting women down?” Obama said. “That’s not acceptable.”

The problem, he suggested, was less complicated than some are making it out to be – and that it often comes down to sexism.

“You’re coming up with all kinds of reasons and excuses, I’ve got a problem with that,” Obama said. “Because part of it makes me think – and I’m speaking to men directly – part of it makes me think that, well, you just aren’t feeling the idea of having a woman as president, and you’re coming up with other alternatives and other reasons for that.”

As CNN reported, Harris had been focused on turning out Black men even before she took over as the Democratic nominee, trying to get the enthusiasm there for President Joe Biden.

“The concern is that the couch is going to win,” one person close to the Harris team told CNN. “We need to make sure that Black men, Hispanic men, don’t sit on the couch. Because if they don’t vote at all. That’s (a) vote for him.”

Harris will travel to Detroit next week for a Tuesday radio town hall hosted by nationally syndicated radio co-host Charlamagne tha God, who announced the plan on Friday morning. He has millions of followers across digital platforms and “The Breakfast Club” enjoys a vast nationwide audience, much of it Black.

During the hourlong conversation slated for 5 p.m. ET, Harris will take questions from callers from across battleground states. An estimated 139 radio stations in markets across the country will take the program, in addition to multiple digital streams and the iHeartRadio app.

As Harris’ campaign works to re-create, in short order, the multiracial Biden coalition of 2020, campaign operatives and allies have been offering a similar directive to the one Obama delivered in Pittsburgh – often privately working to make the case to voters in close-up, intimate spaces.

Last month in Milwaukee, Harris’ brother-in-law, Anthony West, quietly attended a local meeting of the NAACP – a technically nonpartisan group whose members are filled with influential, mostly Democratic state activists and organizers.

In a recording of the meeting obtained by CNN, he made the case for Harris in strong terms.

“Remember you were raised by a strong Black woman, a strong Black woman took care of you, fed you, gave you an opportunity in life,” West told the NAACP audience, urging those in attendance to take the message home.

‘Get off your couch and vote’

At the rally, Obama delivered his most personal, furious indictment yet of Trump and a Republican Party he said is in thrall to a toxic character whose lies about storm relief over the last week marked a deep violation of Americans’ trust.

“The idea of intentionally trying to deceive people in their most desperate and vulnerable moments – my question is, when did that become OK?” Obama said, pointing to Trump’s lies about the federal government withholding assistance to hard-hit “Republican areas” or “siphoning off aid to give to undocumented immigrants.”

When a cheer rose up, he sharply quieted the room.

“I’m not looking for applause right now!” Obama said, his voice vibrating with emotion, before he asked Republicans and conservatives allied with Trump, “When did that become OK? Why would we go along with that?”

Obama drew sharp contrasts on policy and character – ripping Trump and talking up Harris on both fronts – and cast his successor as the mascot for a dangerous and increasingly nasty version of the country. Obama in past campaigns has relished mocking and criticizing Trump, but his speech and delivery on Thursday were stinging and unusually visceral.

“If you had a family member who acted like (Trump), you might still love them, but you’d tell ‘em, ‘You got a problem,’ and you wouldn’t put him in charge of anything,” Obama said. “And yet, when Donald Trump lies or cheats, or shows utter disregard for our Constitution, when he calls POWs ‘losers’ or fellow citizens ‘vermin,’ people make excuses for it.”

Turning his attention to voters who have expressed concern about Trump’s potential return to the White House and others who might not be paying close attention to the campaign, Obama issued a blunt call to action.

“Whether this election is making you feel excited or scared, or hopeful or frustrated, or anything in between, do not just sit back and hope for the best. Get off your couch and vote. Put down your phone and vote. Grab your friends and family and vote,” Obama said. “Vote for Kamala Harris.”

Obama also sought to push back against an argument that has been at the core of Trump’s campaign: That he represents a departure from the stale status quo.

“I get it why people are looking to shake things up. I mean, I am the ‘hopey-changey’ guy. I understand people feeling frustrated and feeling we can do better,” Obama said. “What I cannot understand is why anybody would think that Donald Trump will shake things up in a way that is good for you.”

Throughout his speech, Obama described Trump as uniquely greedy and duplicitous.

Trump’s tax plan, he said, was a giveaway to “to billionaires and big corporations.”

Trump’s pledge to impose harsh tariffs on foreign trade, Obama said, amounted to a glorified “sales tax” that would cost the average family thousands of dollars.

Trump’s claim to having guided a robust economy, he fumed, was ahistorical nonsense.

“Yeah, it was pretty good (when Trump took office in 2017) – because it was my economy,” Obama said. “It wasn’t something he did. I had spent eight years cleaning up the mess that the Republicans had left me the last time. So just in case everybody has a hazy memory, he didn’t do nothing except those big tax cuts.”

Trump’s promises, Obama concluded, were either outrageously false or dangerously simple.

“If you challenge Trump to elaborate and enumerate his ‘concepts,’ he will fall back on one answer,” Obama said. “Doesn’t matter what the issue is, housing, health care, education, paying the bills – their only answer is to blame immigrants.”

This story has been updated with additional reporting.