Manny, I generally enjoy reading what you write, but I think you’re way off the mark here. Your argument is based on a lot of assumptions that just don’t hold up to scrutiny.
One of these is the assumption that Trump’s base is the “white working class.” The median income of Trump supporters was $72,000 a year, which was nearly $20,000 higher than the national median at the time of the election.
Also, you’re committing the common fallacy of assuming that the electorate is static and that it’s a zero-sum game, i.e. that the object is to peel off the mythical “moderate Republicans” and swing voters. Most of the people who consistently show up to the polls are straight-ticket voters who would never flip. There are some Obama-Trump voters, etc. but they’re a relatively small group and they’re hardly decisive.
In my opinion, the path to victory lies in mobilizing the eligible voters who never turn out—which is more than half—because they feel disenfranchised and they lack someone who actually represents their interests, namely young people, poor people and people of color. Bernie Sanders leads among all three of these groups.
With regard to what you said about Sanders having powerful interests opposing him, I don’t think that matters as much as it used to. Not to say that money in politics doesn’t matter at all, but I actually think it’s losing some of its power, and the 2016 elections showed that. Trump spent less than Hillary but won the most “earned media.” It’s more about enthusiasm, viral messaging and having a strong ground game.
I also don’t think him being a socialist hurts him as much as you’re assuming it will. It certainly didn’t in the last debate.
Lastly, if Bernie isn’t electable, then who is? I can’t think of any of the primary contenders who have a better chance of beating Trump. You could maybe make the case for Biden, but that’s relying on those same common sense assumptions I referenced about who goes to the polls. No one is enthusiastic about Biden. I can’t imagine anyone knocking on doors or manning phonebanks for him.