It means "yes according to what you literally said, no according to what you'd have to mean for what you're asking to make any sense".

The reduction in discrimination against Jews has a progressive component and an anti-progressive component. So literally speaking, a "significant part of the reason there is less discrimination" is progressive. But the whole thing is not.

I didn't ask about the whole thing -- I asked about a "significant part." But anyway, let's do this: Please tell me the three most prominent American industries over the last 50-years in the United States where (1) there has been a reduction in employment discrimination against Jewish people; and (2) the reduction was primarily anti-progressive in terms of its' "component."

Since you have specified that the club is WASPy, you are no longer asking whether someone would approve of discrimination against Jews, you're asking if they would approve of discrimination against Jews and in favor of white Christians--a subcategory of that. It is entirely plausible that that subcategory of discrimination is more supported by the right, while discrimination against Jews in general is not

So are you saying that reduction of discrimination against Jews in favor of White Christians probably is, for the most part, consistent with modern progressive political views?

Also, the question asks if P(not progressive|discrimination) is large. Even if this is true, it would not imply that P(discrimination|not progressive) is large.

And even if that were true, it wouldn't matter. Because the real question is which is more consistent with modern progressive political views -- continuing to keep Jews out of the country club or letting them in. I take it you concede that it's the latter?