Mary Margaret tornou-se prefeita no episódio "White Out" , o segundo episódio da quarta temporada.
A blackout strikes the town. David and Emma investigate the issue at the border as Mary Margaret stays home. Unexpectedly, Granny, Happy and Leroy persuade her into fixing the power issue. She balks, as this is a task for the mayor, but they believe Regina no longer wants the job. Granny stresses that Mary Margaret cast the last curse, so she must step up. Additionally, Leroy recalls they reclaimed her kingdom in the Enchanted Forest, but Storybrooke is her kingdom now, so she has to rule it.
Clipe da cena apropriada:
Esta cena deletada do mesmo episódio tem Regina passando a prefeitura para Snow (ao invés das pessoas da cidade):