By Joseph Ax
(Reuters) -U.S. Representative Lucy McBath has been a rising Democratic star since 2018, when she ended 40 years of Republican dominance in a suburban Atlanta seat.
Congresswoman Carolyn Bourdeaux staked her own claim to fame in 2020, when she captured the district next door and became the only Democratic House candidate in the country to flip a Republican seat that year.
But a new Republican-drawn congressional map aimed at eliminating one of their seats now has the two women squaring off for their party's nomination in Georgia's reconfigured 7th district. That ensures only one will advance from Tuesday's primary to November's general election, to the irritation of activists who spent years turning Atlanta's suburbs Democratic.
"I was really frustrated with the process of redistricting," said Mary Baron, a retired attorney who volunteered for McBath's two previous runs and donated to Bourdeaux's campaign. "It seemed clear to me that they created it to put a Republican into office."
The race is one of a half-dozen around the United States in which redistricting has pushed incumbents from the same party to run against one another, an awkward result of the once-a-decade process of drawing new congressional lines.
The rare contests often serve as a proxy for the larger tensions roiling each party - which, this time around, means establishment Democrats and Republicans competing against the progressive left and Trump-dominated right.
In New York this week, a court-appointed special master released a draft congressional map, after the state's top court invalidated a Democratic-drawn plan as an illegal gerrymander.
The new proposal could pit two pairs of Democratic incumbents against one another, including powerful representatives Jerry Nadler and Carolyn Maloney, who have each spent three decades in Congress and will face off this August in what will be a massively expensive primary.
In some states, such as Georgia, the intraparty contests stem from a deliberately partisan effort by one party to draw favorable lines.
In other cases, the match-ups are an inevitable outcome of redistricting. West Virginia lost one of its three seats as a result of sluggish population growth, forcing two incumbents to face off. Republican U.S. Representative Alex Mooney defeated fellow Republican congressman David McKinley in last week's primary election.
In Illinois, Republican first-term U.S. Representative Mary Miller - endorsed by former President Donald Trump - is going after fellow Republican Rodney Davis, who has served a decade in the House.
Miller, a member of the far-right Freedom Caucus, has attacked Davis for his vote in favor of a bipartisan commission to investigate the Jan. 6, 2021, riot at the U.S. Capitol. Davis, who is seen as a more traditional Republican, has the backing of the state's party infrastructure.
New York's new map immediately highlighted the antagonism between the Democratic Party's establishment and left wings. Sean Patrick Maloney, the chair of the national Democratic Party's congressional campaign arm, announced within minutes of the map's release that he would run in a new district made up mostly of liberal Black Democrat Mondaire Jones' seat.
Jones criticized the decision in an interview with Politico but has not said whether he will challenge Maloney. Jones could also run against Jamaal Bowman, a fellow first-term Black progressive Democrat, who occupies a neighboring district.
The Georgia race has been particularly galling for Democrats, given that McBath and Bourdeaux's victories were notched in suburban Atlanta - ground zero for President Joe Biden's surprising statewide win in 2020, as well as for twin Senate runoff elections in 2021 that gave the party control of Congress.
Bourdeaux has attacked McBath for abandoning her district, which was redrawn to be heavily Republican, rather than fighting to keep it.
"Everything that we have been fighting for, you have been undermining by coming and fighting me here," Bourdeaux said at a recent debate.
McBath has responded by noting that polls suggest she is leading the race, arguing that shows voters know her and the work she has done on their behalf.
(Reporting by Joseph AxEditing by Colleen Jenkins and Rosalba O'Brien)