They will both lose because split ticket voting doesn't exist anymore. /hacks
But in all seriousness, Portman is probably running the best campaign of any Republican Senator this year. Strickland's record as governor is pretty terrbile, but there is no other Democrat in Ohio who could have made this competitive IMO. Still, the fact that Strickland is struggling so much in a presidential year doesn't bode well for Sherrod Brown in 2018.
Strickland's not an incumbent while Brown is. I'm not saying that Brown won't be in trouble, but comparing this race to Browns is comparing apples to oranges.