Romney was apparently critical of Santorum for supporting Spectre.
Apparently to the author this is being critical of Santorum for supporting Roberts and Alito.
Quite a long chain of non-causality from one to the other!
Romney’s point, such as it was, was that Santorum was responsible for Obamacare because he endorsed Specter and Specter was the deciding vote for Obamacare. The headline would have been more accurate if it said “Romney Attacks Santorum for Supporting Obamacare.” It was a terrible stretch by Romney and a lousy response by Santorum, who could have just said he had no way of predicting that Specter would switch parties years later.