populist

1. A supporter of the rights and power of the people.
2. Populist A supporter of the Populist Party.

1. Of or relating to populism or its advocates: a populist aversion to business monopolies.
2. Populist Of or relating to the Populist Party.

n.

A fossil patriot of the early agricultural period, found in the old red soapstone underlying Kansas; characterized by an uncommon spread of ear, which some naturalists contend gave him the power of flight, though Professors Morse and Whitney, pursuing independent lines of thought, have ingeniously pointed out that had he possessed it he would have gone elsewhere. In the picturesque speech of his period, some fragments of which have come down to us, he was known as "The Matter with Kansas."

The noun has one meaning:

Meaning #1: an advocate of democratic principles
  Synonym: democrat