Rep who's not a Rep.

DEM

This political abbreviation stands for the opposite of the party mentioned in the clue.

This clue plays on the abbreviation "Rep," which can mean both "representative" and "Republican." The phrase "Rep who's not a Rep" hints at a representative who isn’t a Republican, leading to "Dem" as the short form for Democrat. It’s a clever twist using political abbreviations to misdirect and then clarify.