swing vote; floating vote
Refers to voters not firmly committed to a particular party, whose support can shift between elections.
The movement of swing votes attracts attention at every election.
To capture floating votes, each party is devising its campaign pledges.
Each party is desperate to win over the swing vote among unaffiliated voters.
The outcome of the election race hinges on how the swing vote moves.
After the final speech, the swing vote flowed to the opposition candidate.
The young candidate won by securing the swing vote in urban areas.