Oh that's easy. Everything KaiserDave said, plus Tilden stands for Papist immigrants and Sumner stands for bigoted Yankees.
So let me get this straight. Tilden who said that the work of Reconstruction is over is less of a bigot than Sumner who stands for the continuation of Reconstruction? That seems like rather flawed reasoning.
Tilden to own the Redeemers (Catholic).
See below.
Finally, Tilden oversaw the gradual reduction of the federal military presence in the former Confederacy, with the result that Redeemers reclaimed control of several state governments in the lower South in 1861 and 1862.
Well would you look at that. So much for "owning" the Redeemers by voting for Tilden. I hope it was worth it to you still in the end.
With Sumner you would have had much more of actually owning the Redeemers, rather than empowering them by reducing the federal military presence.