We call most of them ex-Marines. However, there are some on active duty and in the reserves and most of them are simply ticket punchers.
Murtha, Glenn, Dellums, Kovac, Ritter, Carville, Garwood, Lonetree, Dennehy, etc.
I had forgotten about Murtha, Carville, and Lee Harvey Oswald. They are among the few who would qualify as “ex” Marines.