A phrase of 'Cast a shadow' may be found in the text of "Recent unrest, in which dozens have died, has cast a shadow over the polls"
How to define 'Cast a shadow' (over st / sb) (Definition):
1. Literary meaning: Sb / St is covered by a shadow | dark
Example: Last night, sorrow cast a shadow over all of people at the funeral procession
What is synonym of 'Cast a shadow'?: Mournful | cheerless
Expressions of other idioms: