Sneering Imperialist/Honest Hearts

Sneering Imperialist is a perk in the Fallout: New Vegas add-on Honest Hearts.

Effects
Sneering Imperialist provides a 15% damage boost and a 1.25x multiplier to the player's V.A.T.S. chance-to-hit when attacking certain groups, primarily tribals and raiders.

Although the perk's description only mentions raiders, junkies, and Zion's various tribals, which non-player characters the perk affects are actually determined by the non-player character's "race" (referring to a game-specific setting rather than perceived racial makeup). This covers a number of groups/factions in their entirety:
 * Dead Horses
 * Fiends
 * Jackal gang members
 * Sorrows
 * Viper gunslingers
 * White Legs

In addition, a number of other groups are partially composed of members of the specified race designations:
 * Freeside squatters
 * Freeside locals
 * Freeside thugs
 * Great Khans
 * Refugees
 * Wastelanders
 * Westside Militia

Finally, a few named non-player characters are covered by this perk:
 * Dixon
 * Joshua Graham
 * Oscar Velasco
 * Pretty Sarah