It's not as if he were Jewish, and it's right after WWII and the chairman of Berkeley's physics department did not hire Richard Feynman since they already had one Jew on the faculty. Another version of the same quote is:
When Oppenheimer recommended a top student, Bob Serber, to be hired, the appointment was blocked by department Chairman Raymond T. Birge, who wrote a colleague saying “one Jew in the department was enough."
Oppenheimer's recommendation of Feynman was not enough: "I may give you two quotations from men with whom he has worked. Bethe has said that he would rather lose any two other men than Feynman from this present job, and Wigner said, 'He is a second Dirac, only this time human.' "
Now, Clauser received the Wolf Prize for his work at Berkeley's Lawrence Radiation Laboratory (Lawrence Berkeley Laboratory) in the 1970s. I gather that he did the experiments on his own, of his own design, using borrowed and otherwise junked equipment (that is, he had no budget, just a paying job). This is quite special for a post-doc. The other recipients have distinguished appointments, and likely had students and assistants and research support (they did their experiments perhaps a decade after Clauser's), and I imagine that their colleagues lobbied for their receiving the Prize, as happens in the case of Nobel Prizes. Such lobbying is quite usual, for the committees solicit letters of recommendation and I imagine they are contacted informally as well. But as far as I can tell, Clauser did not have such colleagues (even among his advisor, his post-doc sponsors, ...). And as far as I can see, when he received the Prize, neither his undergraduate institution, Caltech, nor his doctoral institution, Columbia, nor Berkeley rushed to claim him as one of their own.*
The archetypal stories concern Gertrude Elion and John Nash. Elion and a colleague at Burroughs-Welcome in Research Triangle Park, NC, won the Nobel in Medicine for the development of AZT. But I guess she was thought not to be the leader, and so she was not then a member of the National Academy of Science; her collaborator was. But the next year, they made sure that she became a member. John Nash, then at Princeton, did outstanding and important difficult and technical work in mathematics early in his career, along with some work on game theory. The game theory work proved central to developments in economics, and the Nobel committee wanted to recognize that. They had two prominent candidates, but the guy who did the earliest work was Nash. Now Nash suffered from schizophrenia, onset in his 20s, and so for most of his career did not have a regular job or do more research. There was no one who benefited from nominating him. (You want to nominate your colleagues or your co-workers.) But the Nobel committee could not award the prize in economics for game theoretical applications unless they included Nash. So they did. And again, Nash was not then a member of the National Academy of Science, but the next year, he was admitted (I think in the economics section, although in fact his professional life was as a mathematician). You can't have such people outside the institutions that are said to include the strongest scientists--and that they had not admitted such people until they were "forced" to is an indictment of the NAS's legitimacy.
So far, Clauser has not become a member of the NAS, but the Wolf Prize has lower prestige than the Nobel. We'll see what happens.
I gather that Clauser is a straight talking scientist, with definite opinions, and he is not much given to brown-nosing. He may well not be very tactful. But if you do important work, someone would figure that that would trump collegiality questions. And keep in mind that at a place like Chicago's Economics Department or many Russian mathematics departments, he would probably be seen as normal.
*Keep in mind that if X wins an international prize, almost always every institution X has been associated with claims X, to the effect that "we have had N Prize winners who have been our students or faculty." If X was on your faculty, and then moves to another institution and becomes even more eminent, usually the originating institution can't help but talk about how it was with X then on our faculty, or perhaps that he did his most important work at our institution. If X won the Nobel Prize while elsewhere, the new institution cannot help but talk about its Nobel-Prize winner.
2. As for decorum and recognition: I have a former colleague, a professor at a very highly ranked department in his field, who is a member of the NAS, and chaired one of its disciplinary sections for a few years. I was told that there were two scientists who were surely deserving and had worked together, but the nicer guy got in well before the less nice one. He also suggested to me that the recipients of honorary chairs in most departments is usually the least obnoxious qualified person (the LOQP).