"Left-wing" traditional politicians are very often insistent that they are the party of "social justice" - especially when compared with their "right-wing" counterparts, but I'm not sure they're actually fooling anyone except themselves.
Obviously there are traditional politicians here and there who have indeed also been great campaigners against privilege and discrimination - but they're very much the exception.
Certainly it is also true that, on average, in modern UK party politics, more advances have been made on equality matters when a "left-wing" party has had the balance of power, and there has been less progress and more regression when "right-wing" parties have had majorities.
I'm not claiming that's a coincidence, but nor do I think it happens because social justice matters are definitionally "left wing" issues.
Left and right
"Left-wing" and "right-wing" are of course simplifications, and "everyone knows" that they don't represent modern politics very well.
Except... depending on how you define politics, they mostly do. In the traditional default definition of politics - the sort of thing that appears in the Politics sections of the papers and news websites, the debates between political parties, the election campaigns and the scandals and so on - a single axis mostly works, at least for politicians and parties relatively near the "centre". Moving away from the centre towards the political fringes, the simplification breaks down - but it works well enough that it's still widely used.
So - what would it mean for equality to be a "left-wing" issue. None of the obvious meanings appear to be true.
It's certainly not the case that all or almost all left-wing traditional politicians are against privilege - many of them are happy to make use of privilege and prejudice to gain some transient political advantage.
Nor does it seem particularly plausible or useful to claim that the "ultimate" left-wing position (if one exists) is a social justice one. It erases the many "right-wing" people who are working for some or all aspects of equality while holding "right-wing" views in other areas, and it likewise conveniently ignores the rampant ablism, cissexism, fat-hatred, and so on present and unchallenged in many "far left" groups.
I've seen it stated as a definitional thing - equality activism is "left-wing", as is environmentalism, or socialism, or liberalism, or various other causes. In practice this seems to end up as defining "left-wing" as "not right-wing" which is utterly useless as a definition, especially when it's followed up with attempts to get the various "left-wing" ideologies to make bad compromises with each other because "they must work together to defeat the Tories".
As a statement of hope and expectation - "equality should be a left-wing issue" - it's hard to argue against; but then, why not equally "equality should be a right-wing issue"? I'll come back to this meaning of the statement below.
In practice, it's not
In practice, I don't see that equality activism does assume that equality is particularly a left-wing issue; while on average there may be more pushing for progress under left-wing governments and to avoid regression under right-wing ones, that's only an average. Our last "left-wing" government had an appalling record on many equality issues - disability rights, fat hatred, immigration, and many more. The approach to traditional politicians of all parties is generally to demand better of them, with very little hope that they'll already be doing enough.
Conversely even our1 current "right-wing" government, while as bad or worse in many areas, has a few areas they're noticeably better - the parental leave proposals in their Modern Workplaces consultation are substantially better than Labour's were, for instance.
The expectation is that being critical of the government and campaigning strongly will be needed whoever is in charge.
The broader political landscape
Rather than imagining the political landscape as a line or a plane, imagine it as a crumpled ball of paper.
The traditional political affiliations can be drawn on one of the relatively flat bits, set out along a fuzzy line from 'left' to 'right'.
Some way round the paper ball, on a much crinklier bit, are the various areas of anti-oppression campaigning2. As it happens, if you cross the outside of the shape, the distance is shorter to the 'left' end of the traditional political line than it is to the 'right' end - but there are plenty of routes across the jagged and folded surface, and some of them come out near the centre or right of the line.
And so it's a struggle to even get most of social justice considered as proper politics - which is to say traditional politics - which is to say the sort of politics which important default people discuss. It's not even, when looking down on the face of traditional politics, on the map. Equality issues get dismissed as "special interests" (collectively, the special interests of 99% of the population, but of course only 0% of the 'important' default population).
Until traditional politics considers the experiences and issues of non-default people to be of equal importance to the special interests of default people, I don't believe there can be any real claim by any traditional politicians to be "the party of" social justice and equality. The "left" may be marginally closer to making that consideration than the "right", but neither, for now, is anywhere near.
For now, most of them are still at best stuck in a compartmentalised mode of thinking where equality issues are separate to all other issues - and generally separate to each other. If it's not a special "thinking about equality" day - they don't.
What would need to change
The majority of people who I see in practice stating that equality is a left-wing issue are left-wing traditional politicians rather than equality campaigners. So, if I take them at their word and assume that they want equality to be a left-wing issue, what would they need to do to actually make it one?
There are basically three things I'd be looking for to show that a left-wing (or right-wing, for that matter) traditional political organisation was actually considering equality to be a core part of its ideology.
- A recognition that there is so much overlap between various forms of discrimination that one cannot productively either consider them in isolation or only work against some of them.
- A complete renouncement of dehumanisation of both opponents and scapegoats, instead focusing on ending the effects of privilege; and the necessary readjustment of policies and justifications for policies to achieve this.
- Successful efforts made to have the officers of the organisation, at all levels (including candidates for public election, if applicable) be at least as representative of all under-privileged groups as the population as a whole.
At the moment I can't think of any major left-wing organisation which is even attempting to do all of those things; quite a few aren't even trying to do any of them.
1 Certainly there are also right-wing parties and ideologies whose ideology is explictly the maintenance and extension of privilege and discrimination. However, just as not all left-wing parties are particularly good on equality, not all right-wing parties are irredeemably terrible.
2 To save space, I'm not even going into the fact that many campaigners against one form of oppression see nothing wrong with and/or deny the existence of other forms - though it is reflected in traditional left-wing politicians who might (for instance) vote wholeheartedly for legislation against sexism while also expressing fat-hatred.