NEW YORK -- For the past four decades, the predominantly black population of central Brooklyn has been represented in Washington by one of its own, a tradition that dates to the 1968 victory of Shirley Chisholm, the first black woman elected to Congress.
But now, in a district whose boundaries were drawn to strengthen black voting power, residents are locked in a wrenching, racially charged debate over an up-and-coming white politician's campaign for Congress.
The candidacy of that politician, David Yassky - who has built a reputation as an accomplished, independent-minded councilman - has led to angry accusations of racial carpetbagging. It has also spawned calls by black politicians that he abandon the contest and that Sens. Hillary Rodham Clinton and Charles E. Schumer, Yassky's mentor, take sides.
But perhaps more important, the hostilities say much about the evolving nature of famously black neighborhoods such as Crown Heights and Brownsville and their profound repercussions on the politics of New York City.
As immigration and gentrification have increasingly altered the demographics of these communities, ethnic and racial blocs that once promoted their own candidates have fractured, with voters choosing among politicians of various backgrounds.
Nowhere is this phenomenon more stark than in the contest for the 11th Congressional District, where American- and Caribbean-born blacks vie for power and a steady influx of whites has heightened the worry that blacks will be displaced from their neighborhoods and the political hierarchy.
At the center of it all is Yassky, 42, a mild-mannered former law professor who, colleagues say, is a believer in the power of government to improve lives. After volunteering on political campaigns over summers during high school, he began working for the administration of Mayor Ed Koch while in college and eventually became chief counsel to the House Subcommittee on Crime, working under Schumer.
As a congressional aide for six years, he said, he "became completely convinced that you could do things that were worth doing," such as the gun control laws and other public safety measures he helped enact.
A Brooklyn Heights resident elected to the City Council in 2001, Yassky emerged as a key voice in pushing the administration of Mayor Michael R. Bloomberg to include subsidized housing in the waterfront rezoning in Williamsburg and Greenpoint.
So when Yassky first heard that Rep. Major R. Owens was retiring this year after serving for more than two decades, Yassky did some soul-searching before he decided to run.
"A big question for myself was, 'Do I think this is the right thing to do, do I think I can represent the whole district, and represent Brownsville as effectively as I can represent Park Slope?'"
He concluded that he could, arguing that the aim of voting rights legislation was, at root, to ensure that minority interests were adequately represented.
"Does that mean that the person who represents that district has to be African-American himself or herself?" he continued. "And I guess the answer is no."
But his candidacy has led to the resurfacing of racial tensions in an area still scarred by the Crown Heights violence that pitted blacks against Hasidic Jews in 1991.
These days those tensions are seen on the political front, over issues such as Yassky's candidacy.
Yassky's critics say that he is calculating that the other candidates will splinter the black vote, allowing him to win by capturing whites, who make up roughly 25 percent of the district.
The contest among Yassky's opponents is also complex, and all have rejected demands that they pull out of the race to coalesce around a black candidate.