It would seem that you are missing the point. The group is made up of people who have sworn to uphold and defend the Constitution who gathered together as a political pressure group to make sure that those following behind them who swear to uphold and defend the Constitution actually do so regardless of the person (i.e., any citizen, having so sworn or not) who is the target when they do not do so.
Intellectually, that might fly. In reality? I'm not defending someone who is a pedophile (for example) even though his land rights are the issue with the BLM. At a certain point, this intellectual fol de rol on the internet gets down to reality in the day to day world. If you are a butthead in the real world, I'm gonna have a hard time getting past that to begin to understand your constitutional problems. Life is too short to ride with ugly women.
On the other hand, if you are a lifelong friend, I may stand with you even if I know you are wrong. The bonds of the tribe are stronger than some law created by 18th Century landowners.