The problem with fighting the Alt-Right is it really requires liberals to do something they don't do well - check their infighting.
If you look at messages between people like Milo and Steve Bannon for example, you'll see a very concerted, concentrated effort to enact change or societal shifts. The left's habit of "we can guilt x into doing Y" only works quite often with people who are otherwise susceptible to that which is often other liberals and it's also not coming as an action "from" some source - it's a collective response of particular groups within liberalism.
So when we talk here about the differences between how a conservative might view a hierarchal system like capitalism vs. democracy, it's very easy to get them to fall in line.
With liberals, you sort of ... really have to keep in mind who your "enemy" is and act accordingly. It's largely the left's inability to do that so they bitch about Bill Maher (not the problem), Sam Harris (not the problem), Joe Rogan (not the problem), The Atlantic (which I found out today I'm supposed to have a problem with), University Professors you disagree with (not the problem), etc...
In that context its insanely easy for Bannon and Co. to pick up white blue-collar because that decentralized behavior on the left leaves two really ugly threads predominant - one ethnocentric and non-white which believes what it believes, and another more mainline but that sort of treats white blue-collar as a "problem to be solved" rather than, you know, just a portion of the population with their own needs while leaving that first group to pretty much do their thing. It's a political calculus that has specific results.
If I could get "all liberals" to behave in lockstep like conservatives though, I'd probably focus on 3 things.
- Build out a rural radio network similar to conservative radio. Focus on centrist issues, not liberal ones (you can get there eventually but that conversation is hard right vs. nothing right now)
- Do what you need to do to get the Berns and AOC's of the world to STOP ATTACKING CENTRISTS. Run liberal candidates where they can win. Run centrists where they can win.
- Quit allowing liberal groups to inform press narratives of specific flashpoints. For example, when I listen to NPR and I hear the term Latinx when there isn't even cultural agreement amongst that demographic that that term is OK.
A lot of the reason you get "reactionary" behavior is when the reaction is to something where the benefit isn't really shown and the pain is. Like the Latinx example - it's easy to pick on because it originates in college where students have ephemeral skin in the game. It's not a terrible idea but it has some drawbacks - it is an English adoption of Spanish, it's clunky, but it does remove unnecessary gendering from the term.
But then it goes to the wild. All of a sudden, a large group of people are using the wrong word - one they may have used for 30-50 years and wasn't a slur. They have to change; they were not consulted (indeed a majority of the people who would fall into the latinx descriptor were not), and people are talking about their continuing use of the "wrong words" in racial or insulting ways. It's catnip for Brietbart and absolute poison for the left.
All of a sudden cogent defenses for "an idea" have to be mounted. People on the left have to "fall in line" on it lest they be labeled racist or centrist and thus beneath being heard at that point. And in "middle america" you essentially have working families that at some point in going to work and coming home 4 years in a row discovering they're being insensitive for using a word their hispanic coworkers don't even use nor ask them to use."
So a lot of what the left does to build the Alt Right is self-inflicted. It's stoppable, but on some level you have to get the buy off "maybe we focus on these 2-3 issues for the next decade and move the line, THEN we attack this other one".
Instead, the left really seems to have recently been on a "lets revisit anything and everything now and if we haven't examined THAT yet lets do that too" without any plan for "how do we get people who aren't used to this idea and their support" outside of we'll just change everything and they'll obviously see the benefit.