ahh.. but.. MtheGM, there is a severe distinctionbetween "us" using the term 'lefty'
as a jocular self-deprecating ironic 'nickname';
and "them" using it as a dismissive term of abuse...

noting that other 'oppressed' groups similarly appropriate established terms of derision
as an act of militant empowerment...

eg, 'Cider Heads'....