But a lot of polling (I'm on more solid ground asserting this about the US) shows substantial support for Democratic (and left-of-Democrat) positions on education, healthcare, etc. while the same public votes nearly split between the 2 parties which are both to the right of their position.
In the UK, apart from the death penalty and immigration, I don't know of issues where voters are to the right of their choices. And interestingly, public perception of immigration numbers is famously hugely inflated.
Tax and defence spring to mind as well:
https://yougov.co.uk/news/2015/11/30/analysis-four-million-labour-voters-lack-trust/
Finally, I can't argue on specifics, but about Attlee: the policy gap between him and Churchill was huger than you paint it for a single reason. Churchill would never preside over the demise of the Empire. Compared to what Attlee did in India, withdrawing from Nato seems like a breeze. You mentioned that the manifestos were similar, I don't know, but I do know that Churchill said that to implement Labour policies it would need a Gestapo.
Additionally, from wikipedia:
Finally, I'm not sure whether it was you or someone else who made the point about centrists acheiving so much more for Labour...the main who created the NHS was no centrist. And he resigned from government due to Attlee's support for the Korean War. He seems to me someone who would fit in better with Corbyn than Blair.
I am not denying that there were huge differences between the parties in the 1945 election. My point was whether the Labour manifesto was as relatively left-wing (compared to the political centre) as Corbyn's policies (which we know of in detail) today.
All three parties endorsed the Beveridge Report in the 1945 election.
Here are the manifesto commitments on health from 1945.
The Conservatives actually had the longest section in their manifesto, pledging:
The health services of the country will be made available to all citizens. Everyone will contribute to the cost, and no one will be denied the attention, the treatment or the appliances he requires because he cannot afford them. We propose to create a comprehensive health service covering the whole range of medical treatment from the general practitioner to the specialist, and from the hospital to convalescence and rehabilitation
although they went on to envision it as encompassing voluntary hospitals and university medical research, as well as focussing on maternity care.
The Liberals had the shortest manifesto of the election, making just 20 points, but still placed health as a priority:
People cannot be happy unless they are healthy. The Liberal aim is a social policy which will help to conquer disease by prevention as well as cure, through good housing, improved nutrition, the lifting of strains and worries caused by fear of unemployment, and through intensified medical research. The Liberal Party’s detailed proposals for improved health services would leave patients free to choose their doctor, for the general practitioner is an invaluable asset in our social life.
and in typical Liberal style, they accordingly released a supplementary pamphlet giving detailed proposals for the practical implementation of such a scheme, which nobody read, but was then largely worked into law a year later.
The Labour party, on the other hand, was by far the most ambivalent of the three. It gave a fairly evasive pledge, envisioning the NHS as little more than an advisory body for healthier nutrition and medical research:
By good food and good homes, much avoidable ill-health can be prevented. In addition the best health services should be available free for all. Money must no longer be the passport to the best treatment.
In the new National Health Service there should be health centres where the people may get the best that modern science can offer, more and better hospitals, and proper conditions for our doctors and nurses. More research is required into the causes of disease and the ways to prevent and cure it.
On the Empire, the Conservatives were supportive of the continuation of Empire (their manifesto is here:
http://www.politicsresources.net/area/uk/man/con45.htm). But the Labour Party's manifesto (
http://www.politicsresources.net/area/uk/man/lab45.htm) did not speak of decolonisation at all, and instead only alluded to self-governance in a similar (but less affusive and direct) way than the Tories.
On Bevan, again you are correct that he was a radical. But his plan for the NHS was controversial even in the Labour Party, and was only passed because of the majority that they won. Whilst it did become law, the key point there is that all parties in 1945 supported the creation of an NHS. There was only a difference on what it would look like and cover. Even then it was the National Government of 1944 (doiminated by Tories) who endorsed the White Paper of 1944. The political centre, and what was considered a 'reasonable' proposal, was markedly different from where it is today, and again the Attlee Government was elected not on radical leftist ideas, but on a manifesto which was not too far away frm the other parties.