There was a time, some eight or nine years ago now, when Britain’s two main political parties seemed to be converging around a never-ending battle for the centre-ground.
David Cameron had recently become Tory leader and, for a while, his efforts to rebrand his party threatened to put it to the left of a New Labour government seemingly more interested in attracting support from the right.
Indeed, it was a legitimate question at the time whether voters of a left-of-centre disposition might be better off under a Tory party seeking to reach out to them than under a Labour administration constantly seeking to define itself in opposition to its own natural supporters.
As a result, we are approaching what will surely be the most polarised election since the 1980s, with the Tories and Labour each presenting very distinctive visions of the kind of country they would like us to be by 2020.
If anyone was in any doubt about this, the keynote conference speeches from the two leaders over the past fortnight will surely have disabused them.
As I noted in last week’s column, the central message of Mr Miliband’s speech in Manchester was obscured by its turgid delivery and the subsequent row over the fact that he had forgotten to mention the deficit.
Yet his attempt to promote the value “togetherness” as an alternative to what he termed the “you’re on your own” society is nothing less than an attempt to smash the economic liberal consensus which Margaret Thatcher created and Tony Blair perpetuated.
But if that represented something of a reversion to a “core vote strategy” by Labour, Mr Cameron’s retreat into his party’s ideological comfort zone in Birmingham this week was even more marked.
Faced by the threat of more defections to UKIP, the Prime Minister opted to fall back on the old Tory mantra of tax cuts and benefit cuts, promising a £7.2bn tax giveaway allied to a £10bn crackdown on welfare spending.
The move appears to have energised the party as well as delivering an immediate boost to its electoral prospects, with a YouGov opinion poll published yesterday showing it ahead of Labour for the first time in two years.
But whether the attempt to shore up the party’s natural support base will turn out to be a victory of short-term tactics over longer-term strategy remains to be seen, with the risk that floating voters will ultimately be repelled by the rightward shift.
Mr Cameron became most impassioned in Birmingham when discussing the National Health Service, accusing Labour of spreading “lies” by suggesting he would ever put the NHS at risk.
Given his own family circumstances, the passion was understandable and obviously heartfelt, but when it comes to the Coalition’s record on health, there nevertheless remains a large gulf between the rhetoric and the reality.
The Tories’ claim to have protected NHS spending over the past four years is an almost empty boast and Mr Cameron’s repetition of the pledge for the duration of the next Parliament is an even more empty promise.
Because it ignores the fact that the cost of treating an ageing population is rising much faster than spending, it obscures the £20bn of cuts that have had to be made just to enable the service to stand still.
Of all the competing visions of the future on offer from the two main parties, the differences between them over health are perhaps the most stark.
The Health and Social Care Act passed by the Coalition in 2012 paves the way for the potential privatisation of the NHS in England, a process that will surely be irreversible if Mr Cameron were to win another term in power.
Labour, on the other hand, has pledged to repeal the Act and is already talking in terms of the election being the last chance to save the NHS in its present form.
It is already clear that outcome of this argument will go a long way to settling the question of who governs Britain for the next five years.