Deleting constraints strange behavior

Why is it that when one deletes an object from a model, it keeps the variable attached?

@constraint(model, con, 2x <= 1)
delete(model, con)
@constraint(model, con, 2x <= 1)
ERROR: An object of name con is already attached to this model. If this is intended, consider using the anonymous construction syntax, e.g., x = @variable(model, [1:N], …) where the name of the object does not appear inside the macro.