I think Nikki Haley resigning is the official beginning of the Republican party breakup.

[GoCubsGo]

9. No, she's trying to salvage her own political career.

Word has it, she took illegal gifts in the form of private jet rides, which is being investigated. She's getting out of the spotlight in hopes that nobody will notice the outcome of that investigation, especially if they uncover additional dirt on her. Which there probably will be. Also, she sees the writing on the wall, and she thinks that if she gets out now, people won't smell the Trump stank with which she has covered herself.

As others have pointed out, Haley is no moderate. She's just another far-right con artist who does whatever is politically expedient for herself. She is as phoney as a three dollar bill, and the "moderate" thing is just another of her cons.