The Civil war is a valid example of our historical struggle with the issue of state vs federal policies, but that was a long time ago.

But I don’t think it’s hard to find, you just have to look for it. Lots of contemporary debates have a strong element of this. For example, the fight over “sanctuary cities” is all about this. Gun control and abortion often involve questions of whether those things are better set at the state or federal level. A huge amount of education policy debate is about how much the feds should dictate. A big part of health care reform is whether it should be done at the state or federal level. Net neutrality is turning into this now that the feds have given it up. I have a hard time thinking of anything domestic where central versus local control isn’t a big part of the debate.