I fell on the animosity side. If there is a major terrorist attack on the US just before the US election, it will be my opinion that some of the blood will be on the Spanish electorate's hands.
Regardless of the debates on WHY the Spanish changed their votes, the reality is that the terrorists concluded that terrorist attacks could affect the election with their preferred candidate to win.
At the end of the day, who do you think Osama Bin Laden or Saddam Hussein would prefer to win?