The antonyms for the phrase "casts vote" would be "abstains from voting" or "refrains from voting". When someone abstains from voting, they choose not to participate in the voting process, which can be either due to their personal beliefs, a lack of interest or knowledge, or a protest against the candidates or the election system. Sometimes, people might refrain from voting as a form of protest, and they choose not to choose a candidate out of principle. However, abstaining from voting can also mean missing out on the opportunity to have a say in important decisions that affect our lives, such as electing leaders or passing laws.