So what is a Caliphate now that we know who wants them? From Caliphate.eu, this is the definition; "The Caliphate is a unique political system from the ideology of Islam that bears no resemblance to any of the Muslim Governments today. It is a government built upon a concept of citizenship regardless of ethnicity, gender or creed and is totally opposed to the oppression of any religious or ethnic grouping.
Non-Muslims have an honorable status in the Caliphate. They are referred to as dhimmi (people of contract), which means they are equal citizens with the Muslims and enjoy the full rights of citizenship. Unlike in Britain they are not given derogatory names like "ethnic minorities" or "immigrants", that implies they are 2nd class citizens and not really welcome. The rights of non-Muslims are enshrined in statutory Islamic Law (shariah) and cannot be reversed by legal precedent or the whims of any government. The Prophet Muhammad (saw) said: "Whoever harms a dhimmi has harmed me." Of course this is a 'Pro-Caliphate site.
Basically from the middle ground perspective (mine if you permit me to use the term middle-ground), a Caliphate can be a benign thing, or a threatening thing. I know that the Republican's have chosen to make it seem akin to the old "Domino" theory that they hawked from 1944 to 1983. It worked well for them then. Maybe that's why they have so much in common with Henry Kissinger and use his "expertise" is their game plan of late.
The Republicans are using this "Caliphate" supposition to back up their new ads that they have launched. I saw one today. They are using quotes from Bin Laden and others to show how much of a threat that they are to America. They are well put together, and with the new terminology will be sure to scare people into voting for the Republicans. People can be coaxed into fearing things that they don't know about very easily, and Karl Rove knows this. All-in-All a Caliphate is just a word. It would be very unlikely that one will emerge in our lifetime in the Middle East. The Republicans will use this word to scare American's and it probably will work. The Democrats should start educating the voters as fast as they can, before the Republicans have a giant conspiracy theory to sell the public again.