On the night he lost the Michigan primary to Romney by 3 points, the exit polls told the story. He could have easily made up the votes to win from some of the women Romney won, the Catholics Romney won, the older voters Romney won, the voters earning more than $100,000 whom Romney won, and those voters with college degrees Romney won. That night Santorum seemed to acknowledge he had let it slip away — he brought out his mom and paid tribute to her education and years as a working mother, as well as his daughter and his wife. And he called Obama’s healthcare law the biggest issue in the campaign, a question of fundamental freedom: “They’re going to give you the right to healthcare; that’s what President Obama promised. But, of course, when the government gives you a right, they can take that right away. And when the government gives you that right, they can tell you how to exercise that right. And they do — not just what doctors you can see and what insurance policies or how much you’re going to get fined if you don’t do what the government tells you to do, but even go so far as to tell you how to exercise your faith as part of your healthcare bill. If the government can go that far with ObamaCare, just think what’s next.”

Combined with his push for fewer business regulations and less taxation, Santorum’s message on ObamaCare was all he needed to win over enough Romney voters to close the gap and beat him. It was the key to his appeal to independent voters, and to those voters focused more on the economy than the social issues Santorum has built a reputation championing.