I think people in this country are just inherently to the right of where the Labour party traditionally sits. Blair dragged it to a place where it could win but it required force to hold it there and once he let go it sprang back. I dont think Labour didnt try to make the case, I think people didnt want to hear it.
Thinking about it this morning it seems to me the turning point might have been in the "debate" - the one where they came on one at a time and didnt actually debate - when Milliband refused to admit his party had overspent. I understood the point he was trying to make, it wasnt Labour spending plans that left us in a financial hole, it was the banking crisis. But the crowd didnt want to hear it. It wasnt Cameron heckling him, he wasnt even in the room, it was the gasps of shock and dismay from the audience, there seemed to me to be genuine astonishment he wouldnt hold his hands up. It felt like the wrong thing to say at the time, given the mood of the room, and I think ultimately it fed into the perception English people have that Labour are essentially profligate and irresponsible, like protecting the vulnerable in society is somehow extravagant or frivolous, rather than a moral duty.
Basically, as much as people care about people being destitute and living off handouts, your average person in this country finds the idea of a scrounger being given a free ride more abhorrent.