SOLVED!!! I went out and took another look and it's definitely the clutch! There is an inner ring of rubber that debonded from the part that mounts to the compressor shaft. I could turn the compressor with a 3/8 ratchet and it's free and turns well. The outer part of the ring is engaging as it should but since the rubber has debonded it isn't connected to the inner ring that drives the compressor. I was able to find the clutch today so I'll get it tomorrow and install. I guess I have these crazy hot temps to blame... Thanks again everyone, especially Dave who convinced me I needed to take another look!