You can still be a card-carrying Communist in New York, but these days committed Communists usually register online.

“We actually have a card, but we don’t make a big deal of it,” said Sam Webb, the national chairman of the Communist Party U.S.A.

The Socialist Party U.S.A. does distribute red cards to members willing to “subscribe to the principles” of the party, but another leftist group, the Democratic Socialists of America, prefers online registration, with members using a virtual shopping cart to pay yearly dues of about $60 by credit card — Marx be damned.

In some ways, the Left remains locked in place. Its three major national parties are still confined to cramped Manhattan offices that are plastered with gaudy posters and honeycombed with pamphlets for distribution and envelopes for stuffing.