326 - 212
With keynote addresses by:
Susana Martinez/Jeff Flake(one of the two)
One of:
Ron Wyden, Howard Dean, Brian Schweitzer, Deval Patrick, or another left-libertarian with strong union ties.
But for labor turnout and a left-libertarian keynote speaker, Sanders would lose Michigan and Wisconsin for the former, Oregon, ME-2, and maybe Washington for the latter. Illinois would be competitive, but Obama campaigning and labor turnout push the margin over 2.5%.
Honestly, if Kasich chose Gardner or Flake or Rubio, he would do a lot better. This the most electable v. least electable, and it's pretty clear who wins.