Combine the broccoli, celery, and red onion in a large mixing bowl.
To prepare the dressing, in a small bowl combine the mayonnaise, lime juice, zest, cumin, chili powder, sugar, salt and pepper. Whisk to combine.
Pour the dressing over the vegetables and stir to combine. Cover and allow the slaw to sit for at least 30 minutes, tossing every so often to combine well. Top with raisins before serving.