This is a tough one. Foreign policy is initially what lead me to politics and why I loved Ron Paul back in 2007.
However, these days I think what is more pressing than anything else is our civil liberties and seems to be a bigger issue more so than it ever has been in this country. Issues we are running into as a result of the insanely invasive privacy violations our government is perpetrating feels more personal than anything else I can remember.
I think at the moment I've gotta go with civil liberties, but sticking to the NAP now and always in the future will prove to be the most important characteristic governing my interests and importance in politics.