sympathizer       
noun [ C ] (UK usually sympathiser) uk/ˈsɪm.pə.θaɪ.zər/ us/ˈsɪm.pə.θaɪ.zɚ/
 支持者;信奉者
a person who supports a political organization or believes in a set of ideas
  He had been a known IRA sympathizer. 众所周知,他支持爱尔兰共和军。 
 Synonym: supporter
Compare: well-wisher