Independent polls carried out on Wednesday, the day before the bombings, showed the Socialists ahead with a slight majority.
A poll carried out by Noxa Consulting on Wednesday gave the Socialists less than a 2 percent margin, putting them, nevertheless, in the lead. A similar poll conducted Friday -- a day after the attacks, gave the Socialists an even greater lead. The big difference -- and the clear reason of the Socialist victory -- was the nearly 3 million votes the Socialists added while Aznar's now not so Popular Party lost about 690,000 votes.
It follows that the bombing and it's aftermath merely strengthened a swing that had already occurred. No doubt bloggers on the right who have comprehensively sprayed the Spanish people for exercising their sovereign right to be masters of their own house will all rush to apologise.
Link via Center for American Progress