How can I stop my male cat from beating up my 2 females?

We have a 1 yr old male, a 5 yr old female, and a 9 yr old female cat. We've had all since they were kittens and all have been spayed or neutered. Everything was fine until about 4 months ago and Sonny (as in Santino Corleone! go figure) started having cat fights with Roxy and Duchess. At first they were horrible as the females tried to fight him. (Try getting woken up from a sound sleep with 2 fighting cats IN YOUR BED!) But now they don't fight back - he just chases them away all the time. He chases away from their food, the litter boxes, anywhere they might be sleeping. We tried getting a large cat condo so all could have their own space and he chases them out of there. It's awful! He's a good cat otherwise. But we can't stand the others being so mistreated. Does anyone think getting him declawed would help? We've never done that because we thought it would be cruel. But maybe it would give the others an advantage. Any ideas on how to stop this? We hate to give him up.