When people think of tribalist Heathenry, it is most often associated with the white supremacist movement of the 1970s and later folkish Heathenry. However, being tribalist does not mean you are a white supremacist or folkish.
Tribalism is simply taking care of the people you hold most dear. When you join or form a Kindred you are creating a tribe. In arch-Heathen times a tribe held ritual together, created and held their own laws and relied on each other in times of need for survival. Heathens today do not have to worry about survival, but surrounding oneself with like minded individuals will help you grow and gives you a solid foundation if trouble or hard times fall upon you.
Secondly, being part of a tribe ties your luck and reputation too the rest of the individuals involved. This is one of the the main reasons why most Heathens take forming/joining a kindred so seriously. Forming a tribe should be thought about for an extended period of time. If a member broke the rules of the group, or even worse broke frith, it likely would have negative effects on the groups luck and reputation. On the other hand, if a member of the tribe does great deeds and gains renown that will have a very positive effect of the group’s luck and reputation.
Members of your tribe are your family, by either blood or oath. These are the people that you would spend time with even outside of rituals and events. For example, going to movies, gaming, going out to eat, etc. These are the people you would call brother and sister, regardless of blood ties. Those titles have great weight and show the over-culture that they have worth to you.
In conclusion, Heathenry as a whole is based on forming a strong community and family ties. All forms of Heathenry are tribalist in some manner. We as a folk grow bonds and take care of each other and the people we care about. These are the foundations of Heathen culture, and tribalism is a necessary part of that.