Final answer:
The sentence 'John Bradley could easily be elected in the next mayoral election' is in the passive voice.
Step-by-step explanation:
In the given sentence, 'John Bradley could easily be elected in the next mayoral election,' the verb 'could be elected' is in the passive voice.
The passive voice is used when the subject of the sentence is the receiver of the action, rather than the doer of the action. In this case, John Bradley is the subject being elected, rather than the one doing the electing.
In contrast, the active voice is used when the subject of the sentence is the doer of the action. For example, an active voice sentence for this statement could be 'John Bradley could easily win the next mayoral election.'