Having lived through all of them
“History has quite a few candidates from further from the center or people who were successfully cast as being extremists who lost by large margins: Goldwater, Humphrey, McGovern, and Dukakis come to mind.”
Goldwater was a “nuke ‘em till they glow” regarding Vietnam extreme hawk. 10, 9, 8, ... daisy ad terrified us. (Whether or not it happened. TW3 (that was the week that was)
LBJ was sneaky.
LBJ was already in a strong position because Goldwater was more extreme right than Eisenhower was, but the daisy commercial put the last nail in the coffin. Lee Atwater and then Carl Rove did good jobs of casting every Democrat they faced as a left wing nut job or just plain silly. Some unforced errors like Dukakis in the tank didn't help.
It's not 1992/2012 any longer. A lot of people were angry that Obama ended up being much more establishment than expected. People who were against Obama care are now clamoring for Medicare for all. Times have changed.
The vocal Democrats right now are far left, but the party as a whole is much more centrist. The Independents are mostly independent because they don't like either party. Some are to the left of the Democratic party, but the bulk are centrists who think the Democrats are too far left.
The Democratic Electorate on Twitter Is Not the Actual Democratic Electorate
Opinion | What Happened to America’s Political Center of Gravity?
If the Democrats believe the Twitter Democrats speak for everyone opposed to Trump, they will either lose or their victory will be very short lived.
I just finished reading the sequel to
American Nations by Colin Woodward. It's called
American Character and was written in 2015. It focuses on the way the different American cultures have interacted throughout American history. He has a prescription in the last chapter for how one party could dominate American politics. He doubted the Republicans could do it because they were too calcified by the time he wrote the book, but he said if the Democrats realize what the interior west and Appalachia want and modify their message to appeal to that and the coasts, they could control both houses of Congress, most state legislatures, and the presidency for a generation or more.
What holds together the Republican coalition is libertarianism. The Deep South, Appalachia, and the interior West are all libertarian, but different types. The Deep South has conned Appalachia and the interior West into thinking they believe the same thing, but they don't. The Deep South believes in economic libertarianism with a very weak federal government and socially they are very authoritarian. The interior West are social libertarians, but are not so anti-government, but don't like too much government interference. Appalachia is very independent and don't like anyone telling them what to do. They are a bit opinionated about what they believe socially, but at the end of the day they would be happy with social libertarianism if nobody was telling them how to think.
Over the last couple of decades the Democrats have turned a couple of interior West states blue: Colorado and Nevada. New Mexico is part interior West, but it's heavy El Norte (old northern Mexico culture) dominates and they are solidly in the Democrat's camp. Montana and Arizona are wavering now.
The more moderate Democrats are pretty much in the interior West's values now, they just need to sell it right. If the Democratic coalition can win over a bigger chunk of the interior West and keep it as well as keep the existing coalition, they have a lock on the Senate and the House until they go too far and part of the coalition is wooed away.
The bulk of the American public is slow to accept big changes. Especially now. The change the left wing of the Democratic party needs to be slow walked or the center will bolt back to whatever the right becomes after Trump. Moving to the left is needed right now and it can be done, but especially at first it needs to be slow walked to keep from scaring the new members of the coalition who need to be recruited to make it happen.