It's not even close. One candidate stands for non-intervention and protection of (remaining) civil liberties. Essentially, returning America back to what it was before statists (both Democratic and Republican) chewed it away throughout the 20th century.
There is no question, if you care at all about returning America to its original ideals. Of course if you're a Republican/conservative statist...then it might be a tough call.
Libertarians...accept no substitute! (Except Ron Paul. He's fine. ;-))