This is a visualisation of ideological positions from amongst different categories supporters of the two main parties. [url=http://www.britishelectionstudy.com/data-object/british-election-study-2015-face-to-face-post-election-survey/Here's the source data[/url - it's from the 2015 post-election survey. Remember then that this is about the Ed Milliband flavour of Labour and the membership of that time. The membership has moved left since then.
To the left is, naturally, more left wing. To the right more right wing. The vertical dotted line is the mean position of all those associated with the party.
Here are the main takeaways from this plot:
1) Members are more ideologically "pure" for both parties than any other grouping
2) Members are ideologically most distant from the voters who get that party in to power, as is again true for both parties.
3) The Tory MPs are further away from their base and more aligned with their voters than Labour is.
4)
Labour MPs are still ideologically closer to the people who will elect them to power than any other grouping associated with the party.
This is why I voted for Corbyn. The distance between him and a pre-disposed Labour electorate is huge. I knew this when I voted for him, and voted for him anyway [url=http://www.newstatesman.com/politics/2015/04/what-overton-windowbecause his presence could drag those voters leftward on that plot[/url.
That time is passed. It is past passed. Get elected, effect change. That's the shape of the world now.
(If anybody knows any PolSci people btw, tell them you know someone who wants them to die. Releasing data in proprietary formats that allow Social Scientists to play at statistics? FFS. Get it in a CSV file and let people choose their own damn tools)
edit: Forgot to include the [url=https://constitution-unit.com/2016/07/05/rules-matter-why-the-current-labour-crisis-is-not-only-about-ideology/link[/url. I didn't do this plot. (But it was done in R and ggplot2, like how what proper people use, and not the nonsense PolSci people think you ought to spend money on)