long story short, I screwed up my rep with the NCR, failing "Don't tread on the Bear".
I want my rep back to where I can interact with NCR. I just went and cleared out the Legion camp thinking that would help, it didn't.
Is there a way to boost my NCR status, or should I just load an old save before I go on?

On the PC you can probably use some kinda console command, on the console I doubt it.
Action and consequence man, your choices has consequences, now, go hunt some NCR and make me proud.

I do indeed hate the NCR, but the way I was RPing, I was hoping to make them hate me in a very special way.
Oh well, there's always another playthrough for that.

Time to go collect some dog tags

What exactly is your rep with the NCR?

I know that Return to Sender can be completed even if you're vilified by the NCR, so maybe if you completed it in a way that gives you positive rep. points with the NCR it would raise your rep to the point where they won't shoot you on sight.

My rep is merciful thug, but after you fail Don't Tread on the Bear, it surpasses any rep you have and your treated as an enemy.

Or atleast that's how it is for me.

I found that Don't Tread on the Bear failed for me when my rep dropped to 'mixed'. They didn't become aggresive afterwards however, even if they gave me a dodgy look, and I was still able to do most of their other quests and even raise me rep back up to 'smiling trouble maker'. They weren't aggresive against me at the battle of hoover dam and were perfectly happy to let me protect thier president, but in my expereience, once I failed Don't Tread on the Bear, I didn't have any chance to complete the main quest with them.

Hey, now... don't just say that and then leave without explaining!

Kill the president me thinks.

Kimball is a [censored]. I have the collectors edition of FONV and I didn't like what he is doing in the background. Bad enough I hate how he handles the Mojave campaign but I guess I should blame Peterson as well...

Anyway, yeah, once you fail "don't tread on the bear" you can't side with the NCR. Not that I cared, heh, heh, heh...

Kimball ascended to office for being a war hero, I suppose he just MIGHT lack in the diplomacy department.

I say let him live to be disgraced after the NCR's loss at the dam. Because as Mr House put it, if he dies he'll die a martyr. He deserves far worse than that.

Haha when i got told by those NCR Rangers for having a bad Reputation for the NCR i tryed the same thing didnt really helped me anyway so i started to work for mr house .

I'm doing my first Legion playthrough and since I'm Vilified with the NCR the Ranger hit squad met me just before the mountain road up to Jacobstown. Conflict ensued and I was shocked, it must have been over in less then 5 seconds. I had no idea that the Embrace of the Mantis King was so damn effective, I had heard tales, but I had never known.