As for the origin of the movement I remember saying exactly this way back in 2008 after the bank bailouts:
(Paraphrasing a bit)
“People don’t realize how much trust has been lost. People want pitchforks. I don’t think they care whether the far left or the far right is handing them out.”
The far left did hand out a few, but they tended to sublimate all their anger into race and minority grievances. Their pitchforks didn’t have enough mass appeal, especially to the white working class killing themselves with opiates.
The right handed out more classical pitchforks with more mass appeal. They went for the old timey scapegoats of immigrant and minority hate and good old fashioned antisemitism (thinly veiled).
They were also the only ones who started talking about “elites.” I remember reading an actual quote on Reddit back then that stuck with me: “if we can’t destroy the financial industry from the left we’ll do it from the right.”
Americans have a short memory. We’ve already forgotten the Bush administration and how it burned a century of goodwill toward our country and a trillion dollars or two in Iraq. We’ve already forgotten how banks that imploded were rescued in such a way as to give the executives leading them a bonus and a promotion for imploding them. (The blame for that goes to both Bush and Obama for doing nothing to intervene.)
So now people are like “where did all this populist rage come from?” They blame crap like gamergate and 4chan when those were just small lightning rods for niche communities. The USA around the turn of that decade was a pile of oily rags waiting for a source of ignition.
The alt right and Trump just saw an opportunity. They didn’t create it, nor did 4chan.