Blue team played appeasing centrists, tepidly allowing to move the politics to the right. Forever suppressing less centrist parts. That is why they lost. They acted like being lower at the pecking order and lost.

Also, electorally the difference was small. The real big problem was the "they go low we go high" ideology, in allowing supreme court be biased so much to the right, reacting too late to gerrymandering, forever trying to be accommodating to republicans.