popularist

Short definition from Wiktionary

Adjective

1. 1
   Reflecting popular taste and opinion.

Noun

1. 1
   An artist or composer whose work appeals to popular tastes.
2. 2
   One who adapts and popularizes a subject.
3. 3
   On who advocates populism.
4. 4
   One who explains social phenomena in terms of popular responses and habits.