I'm don't feel like a very robust political analyst here so open to be corrected but I think it's possibly fairly simple in the sense that the far right / fascism arises out of 2 main elements:
- Economic hardship / decline of some kind, particularly where this results in unemployment, underemployment or a lack of rewarding employment particularly for men.
- Disengagement with politics / democracy or a feeling of having been disenfranchised because they are not directly exposed to the machinery of politics, they feel powerless
I think the mistake of the left is to make this about values - because values are often so important to people on the "left" (not without good reason) they assume that is true for everyone, or that people must be persuaded to share their values. But people voting for fascism, I believe, essentially aren't voting on a basis of values. Even the idea that they are, but their values are "different" and mustn't be dismissed / patronised I think are mostly barking up the wrong tree.
I think this is not about thinking but rather about feeling - those feelings are angry and powerless. Feelings which are validated by the big mean guy that says your anger is GOOD and I will make YOU powerful.
The left / democratic / intellectuals have never been able to deliver this message, and I don't see how they can. It's very persuasive / alluring but also divisive, toxic and fundamentally in opposition to leftist/ democratic values.
So the alternative is to make people feel less angry, less divided and more engaged with democracy so that the alluring message has less power. This is difficult when the very systems that exist within and around fascism intentionally mislead, stoke division and anger, and keep people down. Fascism literally takes away the people's power whilst selling them on the idea it is going to make them powerful. Even in ways that don't relate to the individual, eg fascism is always or almost always accompanied by nationalism "make America great (eg powerful) again".
I think if most of the people who voted for Trump, had a rewarding employment, sense of a meaningful role within their community, and could see democracy in action on their behalf on some level that would go a great way to undoing the power of fascism's false promises. More than education, much more than appeals to higher values. There's a reason the left are often called "elites" and privileged. It's because often they are and that's why they don't need the hope fascism offers (and may be more inured to its effects by the privilege of education).
So basically this is getting a bit rambling but if the left wants to advance it's values, it first has to be electable. I think for that the very first goal has to be JOBS, always. Liberal democracies can protect themselves by ensuring everyone (and most especially unskilled men) has a good job and that meaningful work pays. In the wake of environmental destruction challenging the endless growth model of capitalism (which is the heart of the current crisis and why all modern fascist movements who rely on a vote are climate change denialists), this will require massive public investment in green / renewable industries and jobs.
I think the second thing is to give people more of a voice. Let the people speak / debate publicly, engage publicly with their democracy instead of in private echo chambers of rage online. I think for the left / progressives we have to move away from identity politics and the right-on politics of "no debate". I think there also need to be democratic reforms that inject more of a sense of participation and representation - however I'm not entirely sure what these should be. The Brexit referendum was an example of how NOT to do this - because of the ensuing damage to the economy.
I know that major structural change in politics would be hard (especially with well funded vested interests actively opposing this) but I can see the current systems in both UK and US for example are leading to most people (on both sides of the political spectrum) feeling rather hopeless, uninterested and cynical - whilst politicians are forced by the system to court a tiny percentage of swing voters.
The good thing about eg Trump voters is that they desperately want to be heard and to make a difference. They want to be part of something. Imagine the power of that if it was channeled into something good.