Trump's choices are limited (Haley, Martinez off the table), so he has to double down on an anti-diversity, but also wants swing state and Capitol Hill help.
Kasich (OH, former Congressman) would be his best bet since doubtful he adds a woman (Ernst, Fallin). Corker and Thune could help in the Senate. Scott helps in FL. Newt's experience helps, but his baggage cancels that out. Christie doesn't add anything.
Warren has some downside with moderates, but makes sense in a base election and reinforces Trump's problems with women since Trump wouldn't be able to resist trashing her too. Kaine's a safer choice, but Trump's not only tone deaf about diversity, he's hostile toward it and wants to turn back the clock.
Dems likely around 52 seats, so Hilary won't be able to jam an ultra judge liberal through, so Jane Kelly (RBG replacement?) probably follows Garland. Latino problem hurts in AZ, CO, NV, and NM, but HRC/Warren, RBG/Kelly, Sotomayor, and Kagan boosts Dems and hurts the GOP nationally now and in the future. Newt's not going to inspire future generations to enter public service.