This echoes my own comments, in that there was no need for Trump to run for president in order to be loathsome. I, too, have been disgusted by Trump, and for decades, not since last summer.
However, personal disgust isn't the point, either of Frank's essay or Trump's message. The author isn't the first to note that there are things Trump and Bernie Sanders have in common (see Pierce, Charles P.), and these things have to do with trade, the economy and normal, working people. What we're seeing this year is the inevitable result of ignoring the 800-lb gorilla.
This isn't to diminish the repugnance of so many of Trump's set pieces, merely to confirm that a valid point is a valid point, irrespective of who makes it. I skip to the conclusion, but you should read the whole essay.
Millions of ordinary Americans support Donald Trump. Here's why, by Thomas Frank (The Guardian)
Trump’s words articulate the populist backlash against liberalism that has been building slowly for decades and may very well occupy the White House itself, whereupon the entire world will be required to take seriously its demented ideas.
Yet still we cannot bring ourselves to look the thing in the eyes. We cannot admit that we liberals bear some of the blame for its emergence, for the frustration of the working-class millions, for their blighted cities and their downward spiraling lives. So much easier to scold them for their twisted racist souls, to close our eyes to the obvious reality of which Trumpism is just a crude and ugly expression: that neoliberalism has well and truly failed.