Last time there was a draft, nobody is going to want their sons or daughters drafted to bring California back.
And yes, there was bitter anger for men coming right off the boats and going right into the Union forces to free slaves. the race riots in New York were pretty bad.
Pretty sure, this time, a draft will be unnecessary.
Unless the seceding states or areas have help,(maybe the UN, maybe the CCP)there are more patriots than there are squawking idiots.