There are two meanings to “USCCB”. The first is the collective of all the U.S. bishops. The second is the central office in Washington DC which consists of dozens of departments and employs several hundred people.
Not every statement that originates from the “USCCB” has the full force of all the bishops behind it. Sometimes, it might be a statement issued by just one department. That statement was probably drafted by the lay staff working in that office. It may have the approval of whoever their episcopal liason is. But even if it does, that doesn’t mean it was brought before the whole body of bishops and voted upon. Sadly, the media makes no differentiation. Anything that comes out on USCCB letterhead is treated as though every single bishop in the country is in unanimous agreement.
That article in the OP is misleading and vastly oversimplifies the issues. It attempts to force the bishops into a particular point of view that goes beyond anything they have said.
What is going on with the HHS mandate is in a completely different league. Here we have virtually 100% of the U.S. bishops speaking out forcefully about how this mandate violates religious freedom and that we “cannot – will not – comply with this unjust law”. In the other case, you have one Bishop who is head of the relevant committee sending a letter to Congress encouraging them to raise minimum wage. The two are not comparable.
Certainly, a Catholic politician should not casually dismiss something that any bishop brings up. But there are certain issues where there is room for differences in prudential judgment. If Santorum or Gingrich disagreed with the bishop because they thought it wasn’t important for people to be able to support their families, that would be a problem. If they said that they wanted to avoid an increase in federal minimum wage because they thought it was better handled on a local or state level (since the cost of living varies quite a lot from place to place) or because they didn’t think the high school kid at the fast food place needs to earn enough to support a family of four, then their disagreement is not over Catholic social justice teaching but over what the best policy is to support that teaching.
(Note, I don’t pretend to know enough about Santorum’s or Gingrich’s history on this issue to know why they did what they did, but I’m just throwing it out there as one possible reason that a Catholic might choose to disagree with that bishop’s request.)
The HHS mandate is completely different. There is no way to paint the requirement of Catholics and the Catholic Church to finance immoral activity as simply a prudential difference of opinion on policy. It is not about policy but about a violation of principle.