ATLANTA — W. Mondale Robinson spent a large chunk of last fall in clubs and bars and concert venues in Georgia, trying to convince disenchanted Black men that casting a ballot — in the 2020 general election, then the Georgia runoffs for the U.S. Senate — could finally mean real change in their communities.

But Robinson, founder of the Black Male Voter Project, thinks the case would be a lot harder to make now. He remembers the exact moment his optimism that President Biden would be different began to fade: when Democrats in May said they were willing to significantly weaken a policing-reform bill to get Republican support.

More disappointments followed. Robinson was dismayed that Biden did not push for changes to the filibuster to enact a $15 minimum wage. He was upset that the president did not try to halt a raft of voting restrictions passed by Georgia’s GOP-led legislature.

“I think the frustration is at an all-time high, and Biden can’t go to Georgia or any other Black state in the South and say, ‘This is what we delivered in 2021,’ ” said Robinson, whose group believes it reached 1.2 million Black men in Georgia. “Black men are pissed off about the nothingness that has happened. . . . Does it make the work harder? It makes the work damn near impossible.”

After an initial burst of support, Biden has seen his approval ratings fall significantly in recent months. A Washington Post average of polls since the start of September shows 44 percent of Americans approve of Biden’s job approval, while 49 percent disapprove.

And polls suggest support for Biden has sunk notably among key Democratic constituencies — Blacks, Latinos, women and young people. Pew Research Center polls found Biden’s approval rating among Black Americans fell from 85 percent in July to 67 percent in September, while also falling 16 points among Hispanics and 14 points among Asians.

Interviews with nearly 20 advocates, activists and politicians in the crucial state of Georgia — which Biden won narrowly, in large part because of support from Black voters, after decades of Republican dominance — give a sense of the sentiments behind those numbers. At the center are Black and other minority voters who helped fuel Biden’s victory but who now see what they consider unfulfilled promises and dwindling hope for meaningful change.

In some sense, the “benefit of the doubt” portion of Biden’s presidency is over. While the president gained initial goodwill among many from simply not being Donald Trump, especially when it came to the coronavirus, now those who supported him are demanding results, and his lack of a devoted base is starting to show.

“If midterms are about enthusiasm and turnout, who do you think is excited to vote on November 2 at this moment?” said Nsé Ufot, chief executive of the New Georgia Project, which has registered more than a half-million voters. “Because it ain’t Democrats. It ain’t Black folks. It ain’t young people.”

It remains to be seen whether Biden’s falling support is a sign of enduring enmity or a short-term reflection of a tough stretch marked by a haphazard withdrawal from Afghanistan, a stalled domestic agenda and a surge in coronavirus infections due to the delta variant.

But the discontent is particularly visible in Georgia, where Democrats had hoped demographic changes and mobilization efforts would offer a blueprint for expanding their electoral map.

Some Biden voters said the president will struggle to keep hard-to-engage voters in the fold if he fails to deliver on the issues that motivated them in the first place, notably police reform and voting rights. And they dismissed Democrats’ efforts to blame the lack of progress solely on the partisan divide.

“There are some things that they are willing to hold the line for and to be more adamant about,” said Christine White, executive director of the Georgia Alliance for Progress, which funds nonprofits across the state. “And I think that there are times where we cower and we believe the rhetoric about partisanship.”

Biden and his aides warn against putting too much stock in poll numbers. In taking on tough issues, they say, the president knew the politics would sometimes be tough. But they say that if Biden can defeat the pandemic, pass his infrastructure and social agenda, and continue making progress on racial justice — and they say they are confident he can — his popularity will take care of itself.

Biden and his vice-presidential pick, Kamala D. Harris, campaigned hard in Georgia, which had not been won by a Democratic presidential candidate since 1992. After the election, it became clear that the U.S. Senate majority would ultimately be decided in Georgia, as a result of unusual runoffs that put both of the state’s seats up for grabs. At a rally in Atlanta, Biden said that winning both seats — and the Senate majority — would unlock a laundry list of benefits.

“The power is literally in your hands,” Biden told Georgians. “You can break the gridlock that has gripped Washington and this nation. With their votes in the Senate, we’ll be able to make the progress we need to make on jobs, on health care, on justice, on the environment, on so many important things.”

But to many of those voters, those changes are nowhere to be found.

Two months after Biden spoke in Atlanta, Gov. Brian Kemp (R) signed a law that places new restrictions on mail and early voting and reduces the number of ballot drop boxes, while criminalizing outside groups that offer food and water to voters waiting in line. Critics say the bill has an outsize effect on voters of color, and Biden himself has called it Jim Crow 2.0.

But Congress has been unable to pass a voting rights law. And the George Floyd Justice in Policing Act — co-authored by Harris when she was a senator — died after a bipartisan group was unable to find a compromise, despite repeated urging from Biden to get it done before the anniversary of Floyd’s death.

One week after it was signed into law, Georgia's Republican-led voting overhaul is facing backlash from a growing number of voting rights advocates. (Mahlia Posey/The Washington Post)

At the same time, many have been disturbed by images of Haitian immigrants, seeking asylum during a tumultuous time in that country, being herded and grabbed at by White immigration agents on horseback. The images, White said, “send a signal to Black people that our government has not done enough to eradicate the racist structural behaviors of law enforcement. . . . The message that comes across very easily through the imagery is that America doesn’t care about Black people, period.”

The White House says Biden has gone to great lengths to help communities of color, including by appointing a historic number of minorities and by weaving racial-justice provisions throughout his pandemic, infrastructure and social-safety-net bills. For example, the American Rescue Plan — the official name of Biden’s pandemic relief law — includes debt relief for “socially disadvantaged farmers and ranchers,” which includes Black, Latino and other minority farmers.

“The Black agenda is bigger than voting rights and bigger than the George Floyd Police and Justice Act,” White House press secretary Jen Psaki said recently.

Aides also say the president has not given up on pushing voting rights and police reform bills through Congress. “Both are hugely important,” Psaki said. “The president has committed to getting them both done. He wants to sign them into law.” Pressed on why Biden has not made that happen, she noted that Congress is “a separate body. You need 50 votes to change the filibuster. You also need the majority of votes to pass legislation into law.”

But activists in Georgia say Biden and the Democrats have allowed themselves to be outmaneuvered. Many mentioned Sens. Joe Manchin III (D-W.Va.) and Kyrsten Sinema (D-Ariz.), moderate Democrats who critics said have played an inappropriate role in stopping Biden’s agenda.

Adelina Nicholls, who leads the Georgia Latino Alliance for Human Rights, said her group knocked on “every Latino door in Georgia” before the 2020 election — but now she is dismayed by the lack of help she says Biden has given to immigrants.

“The concern that we have is that the Democratic Party, they keep repeating the same mistakes,” Nicholls said. “We worked for something here. Let’s try something new. Let’s be different. What good is a politician that doesn’t work for the benefit of the community that elected him?”

Helen Butler, a longtime voting rights activist and the executive director of the Georgia Coalition for the People’s Agenda, said she has been dispirited by the administration’s insistence that there is no way around the filibuster — and by how it has prioritized an infrastructure bill as voting rights are being stripped away in Georgia.

“If people aren’t able to vote for people of their choice, then it doesn’t matter what infrastructure bill you put in now,” Butler said. “What will it matter, if they don’t have access to the ballot?”

Biden was elected by people with differing priorities united by their antipathy for Trump, said Michael Thurmond, CEO of DeKalb County, which includes many of the suburbs around Atlanta. And he had to give priority to addressing the coronavirus pandemic, Thurmond said.

“As critical as all these other issues are — and they are — the existential threat to America was coronavirus, a virus that killed 700,000 Americans,” Thurmond said. “I don’t think he’s gotten enough credit for the American Rescue Act. You don’t get credit for the lives not lost, or the money saved, or the people not evicted.”

Robinson, the leader of the Black Male Voter Project, said that his days of reaching out to reluctant voters are not over and that he hopes Black men in Georgia will reliably show up to vote in future elections. But with little movement on the issues that matter most to the group, he thinks the conversations will be a lot tougher next election cycle.

“They can’t call me and ask me to serve my brothers up on a platter for their benefit,” he said. “They can’t have my data, they can’t have access to what I know about Black men from the work that we do, unless I see something serious for Black men. And that requires a conversation with [Black men] long before Labor Day on an election year.”

Scott Clement in Washington contributed to this report.