ideologue

noun

1. A person who advocates an ideology, especially as an official or preeminent advocate.

   “An examination of the Nie et al. party and candidate levels over time (shown in Figure 10) reveals that the changes in the number of ideologues in the levels from 1960 to 1964 were caused entirely by changes in the candidate index.”

   “Lin Biao's fall reduced the contending political groups to radical ideologues and bureaucrats, the latter headed by Zhou Enlai. Mao tried to bring the two warring groups together, relying on the ideologues to maintain a revolutionary momentum, while counting on the bureaucrats to preserve order and run the economy.”

   “The concept of ideology has its origins in the 19th century and was first used as a technical word by Destutt de Tracy. He was also considered the first ideologue, since he applied this word as a substitute for metaphysics.”