Neoliberalism is no where near as popular as it used to be. The neoliberal faction is about as weak as it has ever been since they came to dominate the party back in the 1990's. It's not really fair to say Democrats refuse to abandon neoliberalism when there's plenty of Democrats actively working to move the party away from neoliberalism for decades, and especially now when they are finally at a place where it looks like it could really happen.