Why would AC clutch circuit keep blowing fuses?

It blows the fuse the instant the AC is activated. This system doesn't use a diode on the clutch circuit or at least I can't find one on the wiring diagrams. Its a 2007 ford fusion

Your compressor froze. Replace the compressor. Check the lines as well.

It is likely due to a shorted clutch coil (no resistance). Check the resistance of the coil and get it replaced if it is shorted. It might be more economical to get the whole compressor and clutch coil replaced at the same time. Only get an OEM compressor and clutch coil.

Bad AC clutch is a possibility.
If it's condenser electric fan fuse instead of the compressor fuse you may also have a bad condenser fan.