That’s because they’re both a coalition, and their voters expect improvement. Often unrealistically from them. To the point that they let unobtainable perfection get in the way of whats achievable.

Whereas Republicans/conservatives are fickle. Driven by their fears. They don’t expect or care about improvement. Just that “others” are hurt worse than them. The GOP itself found out the hard way that it isn’t really power. Someone always eventually comes along with equally empty promises and rhetoric but simply a more extreme tone. To steal their sheep away. All that borrowed and abused power evaporating completely. Because it was never theirs.