If you "see" water, then there must be air, otherwise, there is no way to see the water except for the debris moving in circles.
So if there is air in the pump basket, it could be a clog further up the pipe. That is always good to check first just to make sure. On the other hand, the air could be in there because the pump is having a hard time priming due to a clogged impeller.
Backflush the suction line first just to make sure since that is easier than taking apart the pump. Take off the pump lid and put a hose wrapped in a wet rag inside the pipe that enters the pump basket and seal it the best you can. Turn on the hose and see if anything comes out of the skimmer.
If that seems clear, then the next step is to take apart the pump. Have you ever done that?