They let other folks in now and then, as long as they play by the rules.
Just look at Clarence Thomas. By any measure, he is a smart man. Dude graduated from Yale Law school in the early 70's when there were very few black folks there. However, major law firms did the same thing back then that Boebert is doing now, and assumed he just got into Yale due to affirmative action, to "tick a box". Rather than blame the inherent racism at the time, he blamed Yale for admitting him in the first place. Which is bonkers, when you think about it.
Once he became a judge, he continued to work to dial back progress made in the 20th century, all because his fee-fees got hurt after law school. And the bribes, don't forget the bribes!