Now imagine yourself a very liberal democrat, one of the 40 or so most liberal, say.
Mitt Romney won, but Sabato awards the Senate seat to democrat Tim Kaine.
This is a way, come to think of it, in which Romney is like a democrat.
1790, "adherent of democracy," with reference to France, from French démocrate (18c., opposed to aristocrate), back-formation from démocratie (see democracy); revived in U.S. as a political party affiliation 1798, with a capital D. As a shortening of this, Demo (1793) is older than Dem (c.1840).
A member of the Democratic party.