People left of center see Trump as someone doing something illegal, or even plotting a coup, primarily because we haven't really seen political power work for us. We haven't seen someone get elected and actually do what the base wants.
Compare right now to 2008. Dems had congress and the white house. People were ready for change. We could have pushed through a national healthcare system, Medicare for all for, something that would have changed the entire political landscape for generations. Instead a compromise was proposed, right from the beginning. We got "RomneyCare" nation wide. The republicans held fast. Not only did they offer zero support for the ACA, they nominated Romney and he ran against his own program! Now that's discipline. He, of course, lost. But the lesson learned was that he was too moderate. And that was right.
This idea that we shouldn't normalize Trump, that he is extraordinary, means he is a politician who actually does what he says to many people. Why do we reinforce this? Is normal a description we want to own?
Remember when Sanders had all these big ideas? I remember patronizing lectures on the limits of the executive branch. Yeah, yeah buddy. Nice ideas, but time to grow up. We couldn't get anything done even if we wanted to, the republicans won't let us!
There are a lot of liberals who understand rules but have no clue about power, both how to fight it and how to use it. This has to change. This means organizing a left wing within the Democratic Party and outside of it. The limits of electability have shifted and we can use that to our advantage. The centrists had their chance and they couldn't beat Trump. We can't afford to make that mistake again.