The author discusses how an assignment plan intended to keep schools socioeconomically balanced spurs a bitter debate in suburban Eden Prairie. The boundary debate in the 9,700-student Eden Prairie, Minnesota, district has been bruising. Eden Prairie adopted new school attendance boundaries this year based on socioeconomic balance, ensuring for now that no elementary school will have more than about 25 percent of students who are eligible for subsidized lunches. The district has seen an influx of immigrants from Somalia, who before the boundary changes were clustered at one elementary school because of nearby affordable housing. The changes, which moved about 1,100 students, provoked sustained and vociferous opposition from more well-off parents in a series of public hearings last year. Superintendent Melissa Krull, who pushed for the changes, took an early buyout of her contract and left in September after 10 years leading the district and 28 years total working in Eden Prairie schools. Though more bitter than most, the struggle echoes others taking place in districts around the country--especially in suburban areas that have never had to confront such racial and economic diversity before. As suburban districts grow more heterogeneous, school leaders are wrestling with how to equitably provide services to students with a variety of needs and backgrounds without alienating other groups in the process.