Laura Kelly.
She got really lucky in 2018 that she was facing Kris Kobach. If she faces even a slightly more rational opponent, she loses.
Kathleen Sebelius got really lucky in 2002 that she was facing Tim Shallenburger. If she faces even a slightly more rational opponent, like Jim Barnett maybe, she loses.
Kansas is idiosyncratic. Don't count Kelly out. She outperformed her polls in 2018 - they were all pointing to a 1-point race. Personally, I think she still could have won against Colyer, just by a smaller margin (+1 or +2 instead of +5).
Obviously she's not going to cruise to victory, but don't underestimate how powerful the "Brownback in disguise!" attack is in Kansas.