“Districts in which one or more minority racial or ethnic groups constitute a majority of the population now make up nearly one-third of all House seats. Correspondingly, the number of representatives who identify as Black, Latino, Asian, Pacific Islander, Native Hawaiian, American Indian and/or Alaska Native has also increased. Around 7 in 10 of these members hail from majority-minority seats, indicative of these seats’ importance in ensuring representation for minority groups. At the same time, people of color are winning more majority-white seats than in the past. Success in those sorts of districts has increased as our politics have grown more partisan, as voters are increasingly likely to back their party regardless of the candidate their party nominates.”
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“after the 2020 round of redistricting, majority-Black constituencies were roughly halved while seats that were 40 to 50 percent Black nearly tripled. Slow population growth in Northern states led to lost seats in reapportionment, which notably increased each state’s population per district and complicated drawing seats with Black majorities. For instance, New York’s three majority-Black districts in New York City became plurality-Black seats as the state lost a seat and the average number of people per district grew by about 60,000. Lines drawn by partisan mapmakers or independent redistricting commissions also affected the number of majority-Black seats. Florida, for example, drew two fewer majority-Black seats after the 2020 census (although those seats remained solidly majority-minority overall) and controversially unwound one plurality-Black seat; the latter move faces continued litigation.
Black representation, like that of other groups, also intersects with our sharply polarized politics. Because voters of color tend to lean Democratic — Black voters overwhelmingly so — concentrating voters of color in one district can make surrounding seats more Republican. As a result, recent redistricting conflicts have largely centered on GOP attempts to pack more Black voters in majority-Black districts to make nearby seats redder and Democrats’ efforts to unpack heavily Black districts to add Democratic-leaning voters to surrounding districts. Lublin’s research shows that Black candidates (again usually Democrats) can regularly win seats that are 40 to 50 percent Black, depending in part on the share of white voters in the seat and how Republican-leaning they are.”
https://fivethirtyeight.com/features/majority-minority-congressional-districts-diversity-representation/