Usually, parties learn from elections that essentially wipe their party out of national politics. Republicans learned from their post-New Deal 60 years in the wilderness that if they just cooperate and work with majority Democrats, they would never get the majority.
Democrats never learned from 1994, an election just 16 years ago that wiped Democrats out of office from Congress all the way down to local dogcatcher.
In 1994, Democrats suffered from their inability to get anything done and the thought that they could never lose their majority. They did and were shut out of national politics for the next twelve years.
Now, Democrats have not learned from their 1994 wreck and almost amazingly, face another horrible election after just four years in the majority. Rarely does a party have two horrible midterm elections within such close proximity.
In the last 60 years, Democrats have faced one really bad election that pretty much wiped the party out of national politics for years, 1994. In the same time period, Republicans faced two, in 1958 and 1974.
Democrats will probably lose 60 House seats in this election and be out of national politics for another l2 years.
Sadly, like in 1994, Democrats will never learn from their mistake.