Newt Gingrich is not suited for any higher office than he has already held.
He cannot even be considered for even the Senate because he tells people what he really believes. That doesn't work because your opposition can take you convictions and bludgeon you with them.
He also has no executive experience and has a high IQ. Yes, Gingrich has a PhD in history and is a college professor. Last prof was Woodrow Wilson, I believe.
Too smart, too honest, too short, too Southern, too frumpy, too nice, too...er...normal.