apparatchik       
noun [ C ] uk/ˌæp.əˈrætʃ.ɪk/ us/ˌɑː.pəˈrɑː.tʃɪk/
 (某政党)忠诚的资深党员;(尤指前苏联)共产党忠诚的资深党员
a loyal and senior member of a political party, especially the Communist Party in the former USSR
  A former apparatchik in the Communist Party, she became a diplomat. 她曾是一名忠诚的资深共产党员,后来成为了外交官。 
 - More examples
 - To some political leaders, the results have shown the envoys to be nothing more than overrated apparatchiks who have made little difference.
 - Most ex-guerilla fighters are in their forties now and have become party apparatchiks.
 - She criticized him as a White House apparatchik who always backs the president.
 - The convention will be a mix of professional politicians, high-ranking party apparatchiks and ordinary voters.