The Trailblazers are a youth organisation for boys and young men of Pureblood wizarding families. The organisation exists to teach its members the right approach to life in terms of how vital it is to protect wizarding culture and traditions, and to resist - actively resist - the corruption of that culture with muggle influences.
While the Trailblazers is a sibling organisation to the Witches League , it is very different in composition and is organised much more along strict military lines with ranks and titles, and an emphasis on discipline, self reliance, courage and espirit de corps.
Membership in the Trailblazers is open to any male of a Pureblood line from the age of eleven and upwards, and training is offered in the skills and spells required to accomplish the organisation's goals - broomsports, duelling, endurance training, survival skills and so on. Magical history is also taught, focussing on wizards and witches from history whose lives have served as good examples of fighting the good fight against the erosion of wizarding values.
The ideals taught in the Trailblazers include courage, honesty, responsibility and an uncompromising approach to the ethics of the group. Members are taught that it is acceptable - praiseworthy in fact - to fight to protect the weak and helpless (of the Pureblood community), to stand up for women in distress (Pureblood women) and to safeguard their own bloodlines (by staying away from Muggle/Muggleborn females).
With such a high set of standards it is perhaps strange that many people outside the Trailblazers view its members as being a set of arrogant, violent, bigoted thugs. Or perhaps not. They have a nice uniform though, and they do look rather splendid all marching together and singing their jolly songs.