Most of them.
How many cops do you imagine will carry out such an order?
Most of them.
___
Sad, but true.
Attrition rates would whittle them down a bit, and give others a reason to just call in sick.
Yes, if that shoe drops, there will be many who lose on the side of freedom, but civilians far outnumber law enforcement, and word would get out. Cops get to drive their cars home. Most don't park their cars in the garage.