Im doing the main quest and have just got to Novac. On the way there I happened across some Ceasars Legion troops who were just finishing off a caravan party. The Mercenaries done some serious damage to the CL Troops before dying so I decided to finish them off. Upon doing so, I was given a negative view by the Legion and was wondering if it is possible to reset this as I am not very far through and don't want to affect the story too much. I also wouldn't mind killing a few more of them when I happen across them. How much of the game does the negative rep affect, including general exploring?

I'll try not to spoil the game for you but at a certain point in New Vegas your rep will return to normal regardless of how much they hate you

So I can slaughter them whenever I see them? Thats great. Im definately NCR all the way.