Thanks, Jacobtm. I was confusing Catalonia with Galicia at the northwest (as opposed to northeast) end of the country. Galicia seems to be quite conservative on the national level, while Catalonia did indeed support Zapatero in the 2004 election and may generally elect Socialists to the Congress of Deputies. I agree that it would be noble for Zapatero to let Catalonia seceed from Spain, but autonomy and secession of course are not the same thing. Will the plan agreed to in the latest referrendum result in Catalonia voters having less of a voice in the Spanish parliament (whether through fewer members in parliament or what - I'm pretty sure the Chamber of Deputies is not elected by first past the post, but if the proportional representation is done by a region-by-region basis you could reduce the influence of voters in an autonomous region by reducing the number of members elected from that region)? That could hurt Zapatero, but Catalonia merely gaining increased autonomy while retaining its citizens' current influence in the Spanish central government wouldn't hurt the party those citizens tend to support unless and until the region actually seceeds or otherwise loses all or some of it's representation in the Spanish parliament.
Yeah, you're right. The article I was referencing was from quite some time ago when the proposal was not in its current form. It was up in the air whether or not it would be more autonomy or full secession. The Economist was just saying that Zapatero supporting these guys could backfire if they did get the votes to secede.