Most have not.
The big reason is that the winner usually spends so much time there, that they have no clue as to how to repeat the win in a completely different part of the country.
The good news for Cruz is that while he was focusing in Iowa, we have been seeing announcements of campaign staff for several other states. He is putting people in place to start the groundwork in those states as well.
The “personality” of the states are about as different as you can get. In one you have mid-western values, in the other you have East Coast Social libertarianism. Southern NH is virtually Boston. Dartmouth, an Ivy Lague school will be good for Bernie.
People in NH like Trumps populist message. They are turned off by Cruz’s evangelical talk.
No one likes Hillary.
Going against 20 Proof gasoline is not a deal killer...