It means the messages coming from the leadership group aren't undermined (eroded) by one mistake (wave).What the **** does that even mean?
Sometimes I wish this bloke would man up and tell the media he hates them, or actually speak in proper English and not in buzz phrases. The supporters deserve some sort of transparency about what he thinks and what's going on. These cliches get trotted out because they're so vague, in the future, they can't be tracked back to him and hurled back at him.