Swann is many things: a sophisticated collector of art, art advisor to the rich, member of the exclusive Jockey Club, confidant of elite members of society. The Dreyfus affair has reduced him in society to one thing: a Jew.
As soon as Swann enters the Prince de Guermantes’s soiree, he is whisked away by the Prince, leading to much speculation among the guests.
[Mme de Guermantes was] dreading the prospect of having to shake hands with Swann in these anti-semitic surroundings. With regard to this, her mind was soon set at rest, for she learned that the Prince had refused to have Swann in the house and had had “a sort of an altercation” with him. There was no risk of her having to converse in public with “poor Charles,” whom she preferred to cherish in private. (IV,98)
Reassured as regards her fear of having to talk to Swann, Mme de Guermantes now felt merely curious as to the subject of the conversation he had had with their host. “Do you know what it was about?” the Duke asked M. de Bréauté. “I did hear,” the other replied, “that it was about a little play which the writer Bergotte produced at their house. It was a delightful show, I gather. But it seems the actor made himself up to look like Gilbert, whom, as it happens, Master Bergotte had intended to depict.”…”The explanation that you have given us,” said Colonel de Froberville to M. de Bréauté, “is entirely unfounded. I have good reason to know. The Prince purely and simply gave Swann a dressing-down and begged to instruct him, as our fathers used to say, that he was not to show his face in the house again, in view of the opinions he flaunts. And to my mind, my uncle Gilbert was right a thousand times over, not only in giving Swann a piece of his mind–he ought to have broken off relations with a professed Dreyfusard six months ago.” (IV,102)
“Yes, after the friendship my wife has always shown him,” went on the Duke, who evidently considered that to denounce Dreyfus as guilty of high treason, whatever opinion one might hold in one’s heart of hearts as to his guilt, constituted a sort of thank-offering for the manner in which one had been received in the Faubourg Saint-Germain, “he ought to have dissociated himself. For, you can ask Oriane, she had a real friendship for him.” (IV,104)
“Don’t you see,” M. de Guermantes went on, “even from the point of view of his beloved Jews, since he is absolutely determined to stand by them, Swann has made a bloomer of incalculable significance. He has proved that they’re all secretly united and are somehow forced to give their support to anyone of their own race, even if they don’t know him personally. It’s a public menace. We’ve obviously been too easy-going, and the mistake Swann is making will create all the more stir since he was respected, not to say received, and was almost the only Jew that anyone knew.” (IV,107-108)
The narrator confirms Swann as Jew physically, with the emergence of not previously noticed characteristics. His face is eaten away with disease.
Whether because of the absence of those cheeks, no longer there to modify it, or because arteriosclerosis, which is also a form of intoxication, had reddened it as would drunkenness, or deformed it as would morphine, Swann’s punchinello nose, absorbed for long years into an agreeable face, seemed now enormous, tumid, crimson, the nose of an old Hebrew rather than of a dilettante Valois. Perhaps, too, in these last days, the physical type that characterises his race was becoming more pronounced in him, at the same time as a sense of moral solidarity with the rest of the Jews, a solidarity which Swann seemed to have forgotten throughout his life, and which, one after another, his mortal illness, the Dreyfus case and the anti-semitic propaganda had reawakened. There are certain Jews, men of great refinement and social delicacy, in whom nevertheless there remain in reserve and in the wings, ready to enter their lives at a given moment, as in a play, a cad and prophet. Swann had arrived at the age of the prophet. (IV,121-122)