Is That Legal?

Yes, that description is largely accurate. CAP was generally referred to as the Concerned Reactionary Alumni of Princeton. Refreshingly, they didn't couch their views in a rational of opposing quotas or affirmative action -- they were simply against the presence of women at Princeton.

The only way in which my memory differs from the article linked in the post is that, to the undergraduate body, CRAP was more of a joke than a serious threat. Outside of the three remaining all-male eating clubs, nobody took them seriously. Unable to atract writers with genuine Princeton connections to their magazine they had to import Dinesh D'Souza from Dartmouth who served as editor of Prospect while at the same time writing much of the material under the pen name L. T. Gray (El Tigré -- Princeton's mascot is a tiger, ha ha).

In retrospect, it was probably a mistake to treat these geezers as a joke, since they now seem set to form a follow-on organization -- Concerned Associated Justices of the Supreme Court.

I dunno. People could assume that membership in a group of 90 or 100 people, who had purged everybody with even a hint of conservative or centrist views, would be a sign of extremism. But then if they hadn't attended UNC Law, they wouldn't understand that the faculty is really comprised of okay people and mostly pretty sharp lawyers, in spite of being uniformly liberal to flat out leftist in political viewpoint. Yep, it would be pretty disturbing to think about what membership in such a group signified, if one didn't know better...

I attended Princeton in the 1970s, and the characterization of CAP is accurate. As LarryInNYC wrote, CAP was a joke to the students and nothing but an annoyance to the administration, somewhat like an embarrassing relative who keeps ranting that the blacks and the Jews are ruining the country. Frankly, I am very surprised that the person you and I served under in the U.S. Attorney's Office in 1990 belonged to CAP, as he put women and minorities in leadership positions in the office. Although I think that Sam should be confirmed, his membership in CAP and his stressing of that membership in his 1985 application do not reflect well on him.

It's a devastatingly accurate description, the best I've ever read, including the ones I've written! I graduated from Princeton in 1976. Articles of mine on CAP have appeared in the Princeton Alumni Weekly in 1986 (two articles) and in the Daily Princetonian in 1986 and 2005.

99% Accurate. The one thing I would change is that it is less John Birch and more Bob Jones. I was a reasonable/intelligent-brand conservative as a freshman at Princeton, and as a clueless freshman I was involved in a perfectly respectable student conservative group. I quit in disgust when I learned some portion of their secret funding came from CAP, and I am remaining anonymous on this one b/c I still feel embarrassed about it.

I'm really shocked Alito would put it on a job application, even for the the Reagan administration. I knew people at Princeton who as undergrads were planning on future elections/senate confirmations and they would never slip up on something like that.

Here is his discussion of CAP in his response to the Senate Judiciary Committee's questionnaire:

Concerned Alumni of Princeton: This was a group of Princeton alumni. A document I recently reviewed reflects that I was a member of the group in the 1980s. Apart from that document, I have no recollection of being a member, of attending meetings, or otherwise participating in the activities of the group. The group has no current officers from whom more information may be obtained.

CAP member Terry Eastland's senior Justice Department position when Alito submitted application explains why he listed CAP. However, there's been nothing to document that he was ever a "card carrying member". He doesn't "remember" anything about CAP except ROTC "stretch" and denies sympathizing with CAP'S causes.
IF he was never the member he claims, he's been repeatedly telling a flagrant lie that should disqualify his candidacy!