Ed Balls has developed into a formidable politician in many ways, but as long as he stays Shadow Chancellor the Tory message of “Would you want to let them do it over again?” remains a very powerful one.
Unfortunately it does not, and here's why: the British people have, largely, not accepted that the Labour government were a total bloody disaster—especially economically.
Quite simply because the British people have not seen any real bad effects from Labour's policies—and those adverse affects that they have experienced they associate with the Tories (or the Coalition).
The majority of the public associate Labour with generous benefits and welfare payments; while those of us who are political anoraks may understand that the price of this largesse is a massive public debt, the vast majority of the public simply don't care.
As far as they are concerned, it doesn't matter that debt repayments are bigger than the education budget; as far as they are concerned, the government runs on magic money that falls from the sky.
The only real warnings about massive debt that the MSM has seen fit to publicise are the riots in Greece—but these are too far away for most people to appreciate that it is even possible for the same to happen here.
And the only pain that people in this country have felt is from the Coalition: as far as the British people are concerned, it is Cameron and his merry men who are raising taxes, slicing benefits and enforcing general cuts.
Because the dire warnings on government debt have failed—from most people's perspective—to materialise into real problems, they feel like they've been hoodwinked.
Increasingly, the Labour government's rule is starting to look like the Golden Years to many and, as such, they are likely to welcome Miliband and his boys back with open arms.
As such, the argument of “Would you want to let them do it over again?” actually cuts very little ice: indeed, the reaction from the majority of people is likely to be "yes, please!"
Furthermore, the Tories have not only utterly failed to make their case for the cuts (such as they are), but they have also reneged on almost all of their promises regarding reductions in regulation: combined with their persecution of corporations, this means that the Coalition do not even have the backing of the business world.
And, needless to say, their about-face regarding the re-instatement of our civil liberties has lost them any possible support from those of a liberal bent—let alone libertarians.
In general, the Coalition are doomed at the next election simply because they have managed to piss off just about every bunch of people in the country. And it is impossible to win a General Election when nobody supports you.
The Coalition have failed to significantly cut the deficit (let alone the debt), they have failed to keep their promises on civil liberties; most significantly, however, they have failed to create a coherent narrative.
And that last is the main reason why they will fail to win the next election.