Here is Santorum clarifying his reasoning:
Of course we care about our jobs, we care about money, but we care about our families...The family is the first economy. If the family breaks down, well, government gets bigger because of the consequences of family breakdown. We see in the neighborhoods where there are no marriages and there are no two-parent families. You can't ignore the reality that faith and family are integral parts of having limited government, lower taxes, and free societies.
We are either gonna be constrained by internal controls, internal restraint on our behavior or we're gonna be restrained by external restraints -- and when people say, "We can live free and people can do whatever they want to do," show me an example of that in human history. It doesn't work.
Right or wrong, do you see why that makes some economic conservatives and libertarians nervous? The family has broken down in many American communities. Lots of kids are born out of wedlock. Fathers are locked up in jail. In some communities, fewer people attend church or subscribe to anything social conservatives would regard as faith. By Santorum's logic, these communities lack an integral requirement for limited government. In his telling, all human history suggests that they're consigned to fail due to the dearth of these internal constraints unless they get some "external restraints." So do Baltimore, Oakland, Memphis, New Haven, St. Louis, and Detroit need big government now? Or should conservatives continue trying to eliminate it?
What about the rest of America?
Though he'd never put it this way, Santorum's logic suggests that either the social indicators he bemoans start trending in a socially conservative direction, or else big government is our inescapable fate. Try selling that to a coalition of Tea Partiers, small businesspeople, and country club Republicans! They may be more socially conservative than the average voter, but they aren't about to agree that big government is the only answer if in coming years there happens to be falling religiosity, more gay marriage, a higher teen birthrate, and more absentee fathers.
This is the dilemma of the social conservative. Either you embrace the Sam's Club agenda of Mike Huckabee, and get dinged by fiscal conservatives for wanting to spend too much on social programs, or you go the Rick Santorum route, toe the line on size of government and spending, tell your fiscal conservative supporters that they need to support you on social issues too or else the whole project is lost, and realize that for a lot of them, there are no circumstances that justify big government -- even the continued breakdown of the American family.
Interestingly, guys like Rush Limbaugh don't seem to recognize this tension. It's on his radio show that Santorum talked about the importance of social issues, and the talk radio host complimented him for it. For Limbaugh, it's important both morally and politically for Republican candidates to take a hard line on issues like abortion -- to be unapologetically conservative -- and anathema to suggest anything so wimpy as a truce with the dread liberal left.