It's when you get screwed over by the higher ups on your side, so you go to the enemy side in anger. It means that your superior "Pulled a Gates", which is screwing you over and/or stealing the credit. You've done a lot for the side, and you've got nothing to show for it except for insults, so you go to the enemy side in anger.
Example 1-God. my manager at Mc Donalds kept taking the credit for my great innovations and lowered my wage as an insult to injury, so I decided to work at Burger king. Yup, I just pulled a Benedict Arnold.

Example 2-I've been screwed over by the Soviet Union. They keep imprisoning me and stealing the credit. I'm going to be a defector. I'm going to pull a Benedict Arnold if this doesn't stop soon.
by Cinder0 November 11, 2017
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Joining the Other side after you got treated like crap by yours.
I'm being treated like crap by my Artistic"friends." Screw them, I'm going to pull a Benedict Arnold and join the Jocks.
by Cinder0 April 8, 2018
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Someone who betrays everything they stand for seemingly out of the blue. Generally used in a political context.

Originated from the real Benedict Arnold, an American general in the Revolutionary War who famously betrayed America.
Dude 1: did you hear about biden changing his opinion about gay marriage
Dude 2: that was decades ago faggot
Dude 1: He's still a dirty benedict arnold.
by Officer Nigger Hater. September 9, 2023
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