I never know which way I will root. I seem to favor clean kills when possible. Lions attacking elephants I root for the elephant. Even water buffalo when it takes them 2 or more hours to make a kill.
I think it’s easy to reflexively root for the prey. If it loses one time, its suffering/loss is immediately obvious to us.
If the predator loses one time, it’s just a little more tired and hungry. But we rarely see what happens if it keeps losing: it slowly starves to death, a process quite a bit more drawn-out and miserable than the 30-second chase experienced by its prey. Offspring may starve as well (of course that could also be true for a prey animal’s offspring).
Prey animals are frequently juvenile (since they can’t keep up with the fleeing adults). We are sympathetic to children/puppies/kittens, so seeing a lioness chase down a baby gazelle seems somehow unfair to us; I suspect this is a popular daydream. Reality is seldom so rosy, but once in a while it really does turn out that way.
I couldn’t vote. I sit on the fence, and fall either way depending on my mood.