I don't think anyone really knew what Harper's personal views on SSM and abortion were, probably not that high in in list of priorities. But no one could doubt his firmness in keeping those issues of the table. Scheer's position  on the other hand is well known and he will be hard pressed to keep Socons from bringing the issue up, if only under the guise of "everything should be up for discussion by MPs". The issue will be like nagging mosquitoes that keep you from concentrating on the job at hand.