Answer:
at his party's national convention
Explanation:
When a country is in election time, several meetings are held in the parties to decide who will be the candidates for the government and will represent the party in national politics, if elected. After deciding who will be the candidates, the party holds a major national convention, where it not only shows its plans for the future, but officially announces the candidacy of those who will have a political campaign financed and supported by that party.
