In this case, the quote you used and highlighted was not said at the same time as the quote in the OP. The latter quote came AFTER Romney attacked Santorum for his I-don't-care-about-the-unemployment-rate remarks. Santorum THEN gave the "clarification" that you quoted, to reporters in an effort to walk back his original remarks which were being used against him.
Too little, too late. His remarks to his supporters stand. His weak attempt to fix it in the realm of public opinion fails.