First to answer the questions:
Can Ridley belong to all-male clubs, while leading an organization with anti-discriminatory policies?
I think if Ridley were truly interested in anti-discrimintory policies and being a good leader of the USGA he would at least resign his membership (or put it on hold or something) while he is head of the USGA in order to avoid looking improper. Of course, some would say this would be discrimination or other such nonsense - but no one is forcing him to become the head of the USGA or to remain a member of Augusta. I would also expect any female head of the USGA to temporarily quit any membership with any women's only clubs for the same reasons.
Should all men's golf clubs be prohibited?
No. Of course, in Golf its kind of strange to have mens or womens only clubs anyway - since its been my experience most people play with same sex groups unless its a couples match. And since there are different tees for different levels and abilties of golfers, even at the all mens or all womens clubs, I really don't see the advantage - unless of course these are all nude clubs and the men are just simply too embarassed to play in front of the women... but I digress and my feminism is showing
Is the LPGA considered inferior to the PGA?
I think it does not generate interest among men - which is problematic for endorsements as so many golf watchers are male so there are fewer people wanting to watch the LPGA. I like the few LPGA games I see (I must admit here I don't have cable, so don't know whats on the golf channel or ESPN1to50). I also sought out a female pro to get some golf lessons from because there are some anatomical differences between men and women that do impact the game (I'm talking more than just strength, since I can out drive my dad)... I like to watch other women play so I can maybe pick up some clues. Maybe if the LPGA competitors started wearing short skirts, women's golf would get as much attention as women's tennis. (Occasionally there is some interest in the LPGA - like when some cute young flirty woman starts playing in short shorts).
Are women treated as second class citizens since they aren't allowed to play in the PGA?
As pointed out they can play in the PGA - In a perfect world, more pro women golfers would aspire to compete in the PGA and the need for the LPGA would dissappear so it could meld into the PGA and we would all be one happy family

However, golf is a strange world I am just entering into, and I think there are some golfers who like the old world unspoken rules of decorum in golf... some would figure we women golfers should be happy we aren't required to wear the victorian corsets and long skirts. I was invited to play with some med students and doctors one weekend, but found myself in the group with two doctor's wives and a female resident. I enjoyed myself, though, because I am not a good golfer and didn't really relish the idea of being in serious competition with anyone - but the resident and I discussed (mostly in jest) the ramifications of not being included in the "boys club" group and how we could miss potential brown nosing points. In the end, I think the face of golf is slowing changing to something more unisex, but probably the biggest barrier to this is the elitist, high class stereotype attributed to many golfers, which keeps so many away.
As far as the reverse discrimination by the LPGA - I wonder how many men are clamoring to compete? And the WNBA - I didn't know that women could compete in the NBA? I think men like to keep the sports segregated by the sexes, because it allows them to maintain that sense of male superiority in at least one aspect of their life (I am speaking in jest of course

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