In PRC political vocabulary,
党代表 specifically refers to the delegates elected to attend a
党代表大会 (Party Congress) of the CCP — most famously the
全国党代表大会 held every five years in Beijing, which sets policy direction and elects the Central Committee. The historical revolutionary sense (a Party-appointed political officer attached to a military unit) survives mainly in writing about the 1920s–40s.