Any Christian can support a Jewish state in Israel, but the term Christian Zionist has a specific connotation: a belief that a Christian Messiah will return to earth in Jerusalem. As a consequence, they believe that Israel and Jerusalem must not be divided. They oppose any two-state solution, and support those Israeli and American politicians opposed to any partition of Jerusalem. 
Dispensationalism is a set of beliefs that God has specific events in working with man.  Among these is that Jews must return to Israel before the Messiah will come; the formation of the State of Israel was a key step in achieving this goal.They may believe in a subset, Dispensational Premillennism, a theological approach that claims that "God relates to human beings via different covenants ("dispensations"). According to Stephen Sizer, it assumes "that the boundaries of the land promised to Abraham and his descendants will be literally instituted; and that Jesus Christ will return to a literal and theocratic Jewish kingdom centered on Jerusalem."