Blackface is taboo to the Liberal Left. No person I know has any problem with Blackface - especially in the context of a Halloween costume.
Northam should resign for his statements on abortion not his Blackface photo - that is the great irony in all of this.
The Left protect their own. So the fact that they are coming out so strongly against him and calling for his resignation so soon, tells me that the Left orchestrated this as a plan to have him removed.