So I just came back to this PC of mine to. Finish up LR and play for the endgame. I was thinking to myself that I would probably do an NCR ending because I like the NCR. It surprise, I looked on my rep screen in my Pip-Boy and saw that I was a Wild Child with them. I didn't remember ever pissing them off, so I looked at my quest journal and saw that I had completed Cass' quest by wiping out the CC and Van Graffs. That must have been how I lost all that rep. My question is, is there any way for me to come back from being so low without reverting a save? It says I failed the 'Don't Tread On The Bear' quest. Anything I can do?

try this link http://fallout.gamepedia.com/Don%27t_Tread_on_the_Bear!

i think wild child alone isn't enough to prevent you from doing a NRC ending.

you must have done too many mainline quests for a major faction. i have wiped out the van graffs several times so i doubt that is causing your problem.