A union (any union) does have a duty to defend each and every member in a disciplinary situation, regardless of the seriousness of the offense. Kind of like being entitled to a lawyer in the justice system.

I will say that during one of the SKW alpa info events, MEC members from another regional provided examples of pilots whose jobs had been saved by alpa...including showing up drunk multiple lines and doing lines of coke on duty, in flight. While I understand the need to defend these folks I do not think those are good examples of the "benefits" of alpa...I would consider those examples as necessary evils.