A card-carrying member of a particular group or political party is an official member of that group or party, rather than someone who supports it.
I've been a card-carrying member of the Labour party for five years.
2. adjective [ADJECTIVE noun]
If you describe someone as, for example, a card-carrying feminist, you are emphasizing the fact that they believe strongly in and try to carry out the ideas of feminism.
[emphasis]
He is a card-carrying romantic, who married his wife only three months after theyfirst met as teenagers.
card-carrying in British English
adjective
being an official member of a specified organization
a card-carrying union member
a card-carrying Communist
card-carrying in American English
(ˈkɑrdˈkæriɪŋ)
adjective
1.
owning a membership card in a specified organization
2. Informal
thorough, genuine, etc.
a card-carrying pacifist
Examples of 'card-carrying' in a sentence
card-carrying
`He approved her going to earth and becoming a card-carrying member of the CPGB.
Forbes, Bryan THE ENDLESS GAME (2001)
I've been a card-carrying member of the Communist Party for as long as I can remember, but that still doesn't make me an ideologist.
MacNeill, Alastair CODE BREAKER (2001)
"I know that's what you and the other card-carrying members of the PC police would have us believe.