I too have been there done that. The thing that impacted me the most was that almost all Mensans are liberal.
I also noted that Mensa has around 50 percent membership among qualified individuals.
In my experience in two local Mensa groups, the Liberal members seems to be there to preen and show off their superior intellect.
Conservatives seldom stay in Mensa because Conservatives have usually got better things to do than exercise intellectual arrogance.
I am glad I joined and am now glad I am out of it.
My experience, too.