Just like Pelosi encouraged the House to pass Obamacare in order to find out what is in it, Clinton evidently wants voters to elect her to the Oval Office so that they can find out what her position on the issues is.
On the other hand, given that one of the very few powers that the states have actually delegated to the feds, expressly via the Constitution, to regulate intrastate issues is to decide policy for the US Mail Service (1.8.7), I think that Clinton could at least discuss the price of postage stamps and delivery times.
Sorry to nit pick but Congress regulates INTERstate commerce that is between states