standard-bearer
1. A military member who carries the flag of their unit. The soldier marched proudly, flag in hand, as the standard-bearer of his unit.
2. The widely-accepted leader of a cause, movement, or ideology. She rose above her contemporaries to become the standard-bearer of the women's rights movement.
the standard bearer
COMMON The standard bearer of a group of people or a belief is a person who represents them. He saw himself as the standard bearer of the right of the party. She's become very much the standard bearer for traditional, family values. Note: A standard is a flag with badges or symbols on it, which represent a person or organization. In the past, a standard bearer was the person who led an army into battle carrying a standard.