POWDER SPRINGS, Ga. — Less than a 30-minute drive from Atlanta, Powder Springs embodies the changes reshaping Georgia politics. Shops and restaurants owned almost entirely by Black proprietors line its downtown center and are frequented by a growing population of young and racially diverse residents. The suburban city elected its first Black mayor in 2015, and the county where it sits, the former Republican stronghold of Cobb, voted for President Biden by 14 percentage points in 2020.

There is one other big change: Powder Springs, a majority Black city, may soon be represented in Congress by Marjorie Taylor Greene.

That development, the result of new district maps drawn by Georgia state legislators, was part of a Republican drive to blunt Democrats’ power. But for residents, the prospect of Powder Springs and another predominantly Black suburb, Austell, being represented by perhaps the most far-right Republican in Congress is raising questions that go beyond partisan politics. Some say they have little trust that Ms. Greene will pay them the same attention and respect that she gives to her white, Republican constituents and fear their voice in Congress won’t speak for them.

“It’s about having someone that’s going to take your phone calls, who’s going to work on your behalf, who’s going to care what happens to your children, who is going to care about making sure you get to your job,” said State Representative David Wilkerson, a Black Democrat who lives in and represents the communities now drawn into Ms. Greene’s congressional district. “That’s what people are looking for.”

The newly drawn 14th Congressional District is a result of a tactic called “cracking,” the practice of breaking up blocs of voters and scattering them across multiple districts to dilute their voting power. It is common and legal under federal law, unless found by a court to be deliberately used to prevent voters of the same race from electing a representative of their choice.

Ms. Greene, who is best known as a bomb-thrower on social media, has said little about how she would represent the communities new to her district if she wins re-election in November. She did not respond to requests for comment.

In November, she told The Atlanta Journal-Constitution that she was unhappy that her district was made slightly less Republican, calling the redistricting process a “fool’s errand that was led by power-obsessed state legislators.” Rather than add Democrats to her district, she said, lawmakers “should have fortified G.O.P. districts for the long term instead.”

Ms. Greene won her seat by more than 50 percentage points in 2020 and her district will remain bright red under the new maps. It will still stretch through Georgia’s predominantly white and rural countryside all the way to its mountainous Tennessee border. Powder Springs and Austell, with their combined population of under 25,000 people, will stand as a lone blue corner in a sea of red in the new 14th District.

To be sure, plenty of Democratic voters around the country are represented by Republicans, and vice versa. But some voters see Ms. Greene’s brand of Republicanism as a particular affront. The congresswoman has followed the QAnon conspiracy theory and questioned whether the Sept. 11 attack and school shootings were real — comments that got her ousted from congressional committees by the Democratically led House.

She is facing a legal challenge to her candidacy after a group of Georgia voters sued to remove her from the ballot. The group argues that her comments in the days leading up to the Jan. 6 attack on the Capitol, including calling the day “our 1776 moment,” helped incite the riot. Ms. Greene testified that she was referring to “the courage to object” to the election results but was not calling for violence.

In February, Ms. Greene spoke at a rally hosted by a prominent white supremacist. She later defended her attendance, calling criticisms an attempt to “cancel” her.

“Marjorie Taylor Greene represents the antithesis of what we believe,” said Robert Richards, a former Army pilot and Baltimore police officer now working as a senior federal government executive. He has lived in Powder Springs since 2016. “Her rhetoric, her demeanor, her discourse in Congress, her discourse, quite frankly, as an American, is just something that is just reprehensible.”

For more than a decade, Powder Springs and Austell have been represented by Representative David Scott, a Black Democrat whose district included parts of Atlanta and its surrounding suburbs. Mr. Scott’s new district now includes a larger share of the suburbs south of Atlanta.

Most people engage with their lawmakers on routine matters, such as a fast-tracked passport renewal, Social Security benefits claims, Veterans Affairs queries or locally targeted legislation. Ms. Greene’s ability to legislate has been limited by her being stripped of committee duties. Much of the legislation she has sponsored is aimed at making political points, such as the “Fire Fauci Act” and a resolution to impeach President Biden. But none of the bills she has sponsored this legislative session are specific to the 14th District.

At a March rally she hosted in her district, she boasted about having voted down every single piece of legislation backed by Democrats.

Mr. Wilkerson, the state lawmaker, said he was most concerned about a possible cutoff in communication between his office and Ms. Greene’s in Washington to address constituent issues. He said he had not heard from her office since passage of the new maps last fall.

Henry Lust, a Powder Springs city councilman, said, “Our cities are growing, we have significant developments that are being put on the table and starting to be implemented. We have a bright future. We do not want to see that bright future derailed.”

Ms. Greene has also alienated some conservatives. She has drawn five Republican challengers for Georgia’s May 24 primary. One, a small-business owner, Jennifer Strahan, has run as a no-drama conservative — helping her garner support from several Republican leaders in the district, including four out of five of the commissioners in one of its largest counties. She says she would reconnect the district to Washington.

“By restoring service to this and not being so focused on being a social media celebrity, it allows us to bring value back to people,” Ms. Strahan said, noting that she and Ms. Greene do share “some overlap” in their beliefs as conservatives. Ms. Strahan trails Ms. Greene in fund-raising and has struggled to raise her profile.

In Powder Springs and Austell, some residents are organizing to try to flex what political muscle they have. DeBorah Johnson, the chairwoman of the Austell Community Task Force, a typically apolitical community group, has led a drive to encourage more Cobb County voters to cast ballots in next month’s primary election. Ms. Johnson said she found the congresswoman’s comments about the Jan. 6 attack particularly concerning.

“She felt like that was just something that should have been swept up under the rug and not considered a riot,” Ms. Johnson said. “That was big in my eye.”

A handful of residents, including Mr. Richards, are plaintiffs in a lawsuit challenging Georgia’s new maps. The lawsuit, filed in December, argues that the new lines are drawn specifically to dilute Black voters’ influence, and violate the Voting Rights Act of 1965 by not allowing for an additional majority-Black district in south Cobb County. The case is unlikely to be decided before the primary election.

In early April, hundreds of Cobb County residents gathered for the “Taste of Mableton,” a first-of-its-kind spring festival, featuring food trucks, live performances and booths for dozens of community groups. Set up in the shadow of a large billboard for Mr. Scott, the event aimed to strengthen ties between residents of the small community, particularly after the Covid-19 pandemic kept many distant.

Mention of Ms. Greene’s new territory next door was met with nervous laughter and eye rolls among those at the festival who were aware of the change. Those learning of it for the first time responded with outrage and confusion.

Elliott Hennington, a community leader who is also a plaintiff in the lawsuit, described the redrawn district as “disgraceful” and “very disrespectful” to the voters now part of it.

“They were shocked, surprised,” he said in an interview behind the Austell Community Task Force booth. “People are just redistricting just to fit their own needs without getting input or buy-in from people in the area — the people who would like to be represented in a fair and equitable manner.”