In our own experiments, we have found that possums and skunks are not very inclined to climb, particularly skunks, which seem to ignore almost everything above the level of their head. Raccoons, on the other hand are incredible climbers and can scale virtually anything made of wood, stone or brick. Feeders that would be resistant to raccoons would need to be raised at least 24" off the ground (probably higher), and need leg or legs that are made from, or covered with smooth, hard plastic. Even at that, raccoons shouldn't be underestimated.
Short of going to extreme measures, the most practical advice is the leave food out for the cats only during the day and pick up any remaining food by sunset.
What is the consequence of leaving food out all the time? Mainly, you will use food much faster feeding more critters! It is rare, though, that cats will tangle with similar size wildlife. They may, however, be discouraged from eating if there are many other critters around the food. Study of literally hundreds of feeding station visits by critters of all types has shown that animals universally are very attentive and anxious while eating because it forces them to stay in one place and focus on their eating, which makes them more vulnerable.So an overly "popular" feeding station may become less appealing to more shy animals.