Take that up with the Democrats threatening to leave the party because of it. Besides, too far left is what won Trump the presidency. This election was ideology & culture more than anything.
Also, not sure you realize how far left Ellison actually is. He's the guy who demanded to be sworn into office with a Quran. Now, I'm not saying anything is wrong with that, his religion, his choice, but if he's the one chosen to lead the party with his vision, as far left as it is, good luck winning back the rust belt.