How can I write a plugin to allow TL1 to ignore users?

I found this code, which seems to be exactly the place I want to override:

I see where it checks the user’s trust level and only allows them if their level is >= :member …I think if I change that to :basic it will let TL1 users ignore.

This code is part of guardian.rb

Is it possible to override this? (Or accomplish the same goal elsewhere in the code?)