Let's say Alice, Bob, and Charlene are all Bluocrats, and Dexter and Edith are Redpublicans. Vote totals for a 3-seat election are A: 1500, B: 300, C: 200, D: 500, E: 100.
Bluocrats have 2000 total votes, Redpublicans have 600.
So effective votes are A: 2000, B: 1000, C: 667, D: 600, E: 300.
A, B, C are elected even though D had more "natural" votes than C.