A Caliphate ain't no stinkin' Republic.
That's like sayin' snakes is angels.
Definition of republic (n)
Bing Dictionary
re·pub·lic
[ ri púbblik ]
1.political system with elected representatives: a political system or form of government in which people elect representatives to exercise power for them
2.state with elected representatives: a country or other political unit whose government or political system is that of a republic