Hanaway. She might not be the best Republican candidate for that race, but McCaskill isn't going to get reelected. If she faces a strong candidate like Ann Wagner and if Clinton is president, she will get Blanched.
I agree. Ha away would win, although Wagner is my preferred candidate. Also, McCaskill isn't exactly a centrist, she's not as liberal as many of her fellow Senate Democrats, and while she's also a good campaigner, it seems, she's noticeably to the left of Tester, Heitkamp, Donnelly, and Manchin, actual moderates who have real crossover appeal. I can see scenarios where any of them survive (Donnelly the least, though,) but McCaskill is doomed unless lightning strikes a third time.