[AnotherUnixGeek]

Nikki Haley is still the strongest VP pick

No. No to the point where I would seriously consider not voting at all if she's on the ticket. I suspect I'm not alone in that. If Trump wants to win, he will keep Haley far, far away from him.

[Verginius Rufus]

Trump might as well pick Liz Cheney as Nikki Haley. The other defeated candidates have mostly come out for Trump and some have been trying to help him. She came out with some kind of weaselly statement to the effect she would vote for him, but she doesn't really support him.

More important than the (probably negligible) impact a VP pick will have on the election is having someone who could be a good President if the President died or was killed. (That was Lincoln's big mistake in 1864, putting Andrew Johnson on the ticket.) Haley would never have a chance of being elected on her own because she wouldn't ever be able to convince people she would make a good President.