The whole thing is taken out of context. Rahm said:
"There are no liberals left to get" in the Senate, Emanuel said in an interview, shrugging off some noise from the likes of Sen. Bernie Sanders (I., Vt.) that a few liberals might bolt over the compromises made with conservative Democrats. (emphasis mine)
He wasn't attacking "the Left", he was saying that... well - JUST READ THE FUCKING QUOTE!!
Jesus, people are about losing their damn minds. Settle the fuck down, y'all!