re: Nikki Haley's possible reasons for staying in the race

It's much simpler than that.

There is still a small chance she could win due to Trump's legal situations or a health issue affecting him. He is 77 after all. (Not that I am predicting that, just answering the question).

If he wins, she is screwed whether she drops out now or later. Plus she won't a job equal to what she had last time. She won't be his VP, if he wants a woman he will choose the one from upstate NY. If he wants a minority it will be Tim Scott.

She is making contacts now and if...IF...Trump loses, she has a head start on next time, she can go around saying "see, I TOLD you he would lose!" but she still has collected a lot of business cards, picked up some donor lists, etc.