Given the remote possibility that you are not already aware of this, please consider the following. Most of the limited powers that the states have delegated to Congress, via the Constitution, are listed in the relatively short clauses of the Constitution's Section 8 of Article I. So if federal politicians like Santorum talk about any issue that you cannot reasonably associate with one of those clauses then they are blowing hot air.
In fact, Santorum is essentially limited to talking about US Postal Service (Clause 7 of Section 8) where domestic issues are concerned, most other federal government services that citizens think are bona-fide federal services, like SS and Obamacare Democratcare, actually constitutionally indefensible imo.
