The phrase "victorious party" refers to a group or team that has won a competition, election, or battle. It represents the winning side or the people who achieved success in some kind of event or endeavor. Full definition
Those responsible for policing the nations's elections might be militantly biased in favor of the erroneously victorious party, and therefore would embrace the error, and make a coup of it. (politics.stackexchange.com)
blackmailed or personally threatened by the erroneously victorious party, and therefore would embrace the error, and make a personal survival of it. (politics.stackexchange.com)
More remarkable in the words of a victorious party is the refusal to recruit God as a partisan. (firstthings.com)