I see more to this story. This just doesn't seem like it “rises to the level” to be something over which a Democrat would resign. A Republican sure would.
There is more to the story having to do with Spitzer wiring money to another state and bringing the hooker in from another state. Prostitution across state lines is a federal offense. So there is more here than meets the eye. Now some in the NY legislature are calling for Spitzer’s impeachment if he refuses to resign.