people who identify as left wing politically form a large majority here

Except they don't: more than 60% of the survey participants identified as liberal or libertarian, and those are right-wing ideologies.

On the other hand, liberalism includes both classical liberalism, which is right-wing, and social liberalism, which is moderately left. I think that the "liberalism" option of the survey ended up including them both. Although it might have been useful to actually make a distinction between them.