The answers are 1, 3 and 4.
communicate an issue to the public:The electoral campaign aims at communicating to the public the measures that the candidate intends to take on certain issues. That is, talk about the ideas of the candidates.
Communicate a message about a candidate: Passing a message about the candidate in the election campaign means presenting the candidate to the voter, telling his or her life story and how he or she came to the nomination.
get a candidate elected for office: this is the main purpose. The electoral campaign is the instrument that aims to elect the candidate to the position of representative of society. It is through the electoral campaign that the voter takes notice of the candidacy, that is, it is the advertising platform of the candidacy.