Well, the more I think about this the less I'm sure, but nowadays I lean towards that view. I would say that Spain didn't become a unitary state until the Bourbons took over the crown after 1713, and that at least since 1830 there has been evidence of strong regional identity movements (political or simply cultural). The First Spanish Republic of 1873-4 was subject to strong separatist tensions (famously, the city of Cartagena declared itself an independent canton), and the Second Spanish Republic of 1936-9 gave autonomy to Catalonia, the Basque Country and was drafting a Galician statute when the Civil War broke out. The Spanish Constitution of 1978 intended for only those three to have full autonomy retaining a unitary (but decentralised) state for the rest, but Andalusia managed to win a referendum to fast-track itself into autonomy, and in less than 5 years the whole country carved itself into 17 autonomous communities. Spain is effectively a federal state in all but name. However, I see a majority of the PP electorate and a sizeable part of the PSOE electorate favouring a unitary state. This was evident during the recent controversy on the reform of the Catalan Autonomy Statute.

We have met the enemy, and he is us — Pogo