Not just Duncan Hunter, but also Rep. Ron Paul.
Of course, there are Republicans who will argue that Rep. Paul is not a "real Republican" because he happens to believe the Constitution of the United States must be followed, in war as well as in peace.
I've not looked into Ron Paul's record on immigration, but a Libertarian running for president as a Republican is not electable in the general election. Thus I must decline to support him in the primary.