Steven Colloton (8th Circuit)
Allison Eid (Colorado Supreme Court)
Raymond Gruender (8th Circuit)
Thomas Hardiman (3rd Circuit)
Raymond Kethledge (6th Circuit)
Joan Larsen (Michigan Supreme Court)
Thomas Lee (Utah Supreme Court)
William Pryor (11th Circuit)
David Stras (Minnesota Supreme Court)
Diane Sykes (7th Circuit)
Don Willett (Texas Supreme Court)
I’m not well acquainted with all of them, but those I do know about — Allison Eid, Thomas Lee, William Pryor, David Stras, Diane Sykes, and Don Willett — I very much respect: I’ve seen excellent, thoughtful, scholarly opinions from them. There are other people I would have put on the short list, but I’m not the presumptive nominee of a major party (and if I were, there really would be a “natural-born citizen” objection to me).
Special twist: If Trump is elected (a very big if) and then nominated and got confirmed Eid, Kethledge, Lee or Stras, that person would be the first justice to serve on the Supreme Court together with the justice for whom he or she clerked (Justice Anthony Kennedy for Kethledge, and Justice Clarence Thomas for the three others). Colloton and Larsen also clerked on the Supreme Court, but for Chief Justice William H. Rehnquist and Justice Antonin Scalia, respectively.