I expect that Durbin would either appoint Bustos, his protege, or Sheila Simon, his mentor's daughter. Either one would be a big blow to the Daley-Emanuel Chicago establishment.
Comment lacks understanding of Illinois and Chicago politics
Can confirm. Chicago never primaries down staters who run statewide.
Durbin gets along very well with the machine. As does Sheila Simon. I presume Bustos will as well.
In terms of the "Daley-Emanuel Chicago Establishment™" and Durbin's particular role in actual city politics, it's a lot more complicated than you allude to.
Take the State's Attorney race that Green Line and I were discussing in my Chicagoland maps thread. Rahm's candidate was Anita Alvarez. She was also a Daley favorite and protege early on in her career. Yet, the Cook County Democratic Party, the current political anchor of the machine, endorsed Kim Foxx, who Durbin also endorsed. People's Pat Quinn also endorsed Foxx.
Chicago elections are littered with examples like this. Even within the "machine" there are factions and the factions oftentimes ally with "outsiders" like Durbin - and this is especially true in recent decades where the machine is not nearly as organized and powerful as it once was.
tl;dr The "Chicago Machine" is complicated politically. I certainly wouldn't claim to understand every aspect, and I live here and follow local politics and news. But I do know that your original comment lacks understanding.
