Tonight David Cameron turned in the performance he needed to. In the post-debate polls, Cameron has won three comfortably, one narrowly and tied the other

For the first forty-five minutes it was rather like the first debate. Brown attacked Cameron, Cameron hit back and all the while Clegg soared above it. But then immigration, Clegg’s Achilles heel, was thrown into the mix. Cameron went hard for Clegg over his amnesty policy, and Clegg had no clear answer—initially backing away from the policy, before coming back to it. Throughout this exchange, Cameron had covering fire from Brown. Clegg appeared knocked back as he came under the most sustained attack of the campaign and didn’t get back into his groove until his closing statement. In the meantime, Cameron capitalised; delivering some of his strongest answers of the whole debate series. As he delivered his closing statement, you sensed that Cameron knew that he had done what he needed to do.

As for Brown’s performance, the story of it was told by Mandelson arriving with a while to go looking glum.