Continuing the theme of tactical voting: South Down.
If the share of the vote that the unionists and the SDLP received in 2007 were applied to the voting turnout of 2010, unionism should have got 13,326 votes (or 31.8% of the votes cast) – but yesterday it got only 8,244. The SDLP, on the other hand, should have got 13,358 (or 31.4% of the total) – but they actually got 20,648 votes (48.5%).
So the unionist total decreased by 5,282, and the SDLP total increased by 7,290. It seems likely that over 5,000 of the SDLP's extra votes were unionists trying to thwart a Sinn Féin victory.
But who were the other 2,000 votes that the SDLP received over its 'natural' vote? Well, a few hundred may have been people who had voted Green in 2007, but it seems likely that even some Sinn Féin voters switched to the SDLP. The Sinn Féin vote yesterday was actually 1,898 votes lower than in 2007. So South Down may have seen a strange combination – unionists, ex-Greens and ex-Sinn Féin voters combining to thwart Caitriona Ruane - this may be a report-card from the voters on Ruane's performance as Minister of Education.