The idea of the electoral college (as opposed to a nationwide popular vote) is that each state is ultimately represented, rather than each voter. Including the state level only makes sense if there's a state-level political affiliation.
What's more, the electoral college is specifically for electing the president and vice president. So you need a country with a strong executive.
The US got its state-level reckoning from a bunch of small sovereign states banding together and not wanting to give up local sovereignty. This seems a relatively rare occurence, but what if an existing country, with a high degree of regionalism, adopts a federal presidential structure designed to protect the voice of minority communities?
I'm specifically thinking of Spain here. So you could mandate an executive be elected among several of the Basques, the Catalans, the Galicians, the Extremadurans, the Cubans, the Andalusians, and/or the Castillians. I'm not sure the numbers quite work out on that, though--there likely are too many Castillians for a balanced distribution.
Furthermore, I have no idea how to get Spain into a situation that develops a CE. But those are my thoughts on the matter.
If, for example, you had said to the Basques in the 1800's that you are going to create a common EC for the three provinces (or the four if you include Navarre), they would have called you a fool and would have demanded an electoral college for each province. Well, actually, except in the cities, they would have refused elections as an impious liberal deviation and cheered Don Carlos and the
fueros, but you get the idea. The idea of the Basque Country as a political unity was created by Sabino Arana a century ago, and even nowadays there is debate inside the basque nationalism about how "unified" the Basque Country should be, at the point that it caused an escision inside the Basque Nationalist Party in the 80's, when
Eusko Alkartasuna was created. In Catalonia,thought more likely, the reactionnary north wouldn't be happy sharing EC with the liberals from Barcelona (and would refuse elections, cheered don Carlos etc), and the Barcelonian bourgeoisie wouldn't be happy with the hillbillys of the north etc. Similar situations would exist in many parts of Spain.
If we are talking about nowadays Spain, there is not reason to create electoral colleges for every community. As in many other parlamientary democracies, the only spanish "Electoral College", the
Cortes Generales, is elected on territorial basis (provincial level) by direct suffrage and it's the body which elects the head of the government. So, Catalonia (mainly Barcelona), Andalusia, Madrid, Valencia and the Basque Country, being the most populous communities (because have some of the most populous provinces), send more MP's to the Parliament and the Senate than, say, Castille and Leon or Castille-La Mancha. Thus there are more catalans, andalusians and basques electing the PM of the, in Falastur's planet, "castilian central government" than castilians. It's far from a perfect system, but the territorial representation is granted. Obviously the Parties system generally prevails over other considerations in the election of the PM, but that has nothing to do with the territorial structure of the country.
Things are much more complex than that story about evil castilians told by Falastur. But in order to realize it it would have required actual knowledge and thought by his part instead of prejudges and stereotypes.
It's not by chance that, since it's origins, all the spanish electoral systems have been based in provincial and/or local levels, for the good and the bad. Even in 1873, with so castilian presidents as Pi i Margall, Figueras or Salmerón and a federalist majority in the Cortes, nobody considered a similar idea. also, the confederalist Cantonal Revolution was mostly based in the municipalities, not in higher territorial levels
However, considering an Electoral College in his broad sense (a body of electors which elects a representative or candidate for an office through indirect suffrage) instead reducing it only to the american system, there is a precedent in Spain.
The Constitution of 1812 established electoral colleges, called
Juntas Electorales working in three sucesive territorial levels. Male citizens, neighbours of the locality and at least 25 years old elected their local
Junta Electoral (
Junta Electoral de Parroquia), this body elected representatives for the judicial head of the zone (
Junta Electoral de Partido) and this body elected representatives for the province (
Junta electoral de Provincia) Then, those electors elected the respective MP's from this province to be sent to the national
Cortes.
Since it was a parlamientary system, like the current system, and as Admiral Brown pointed the american EC system is conceived for a presidential republic, there is not reason to expect otherwise.
On the other hand, a bit off topic, but you are mixing Castille properly (the two Castilles) with the historical territories of the Crown of Castille. The Crown of Castille would have a large majority of population, but it includes Biscay and Alava, Galicia, Andalusia, Extremadura etc. Castille properly is rather underpopulated.
By the way, aren't the French senators elected by electoral college? I mean, not like the american system but Electoral College after all.
Cheers.