AFAIK, the only way to functionally take out the Powder Gangers is to join them and then eventually turn on them. Is there any way to activate the NCR raid without working for them at all? I'm playing a Good Natured character, and doing anything for those guys seems against my nature. Not to mention, it seems odd that the only way to really take them down is to join them. I know I can solo the prison and wipe them out myself, but apparently this doesn't count at endgame. So, any thoughts? Thanks.
If you just want them dead, you can shoot up the prison on your own.
Activating the raid, supposedly you can bribe Dawes to get in and then do Eddie's quests (non-violently), but not if you have negative rep with them, which is tricky since many of them are aggressive.