Yes, anyone who perceives him as an outsider is making a mistake. A New York billionaire who allies with other billionaires isn't an outsider.

What I don't understand is how the fact of his corruption has failed to take hold over the past nine years and what we could ever say differently to make it take hold.

On Wikipedia, as just one example, there's useful info in Wealth of Donald Trump and Tax returns of Donald Trump and Personal and business legal affairs of Donald Trump. It's not esoteric knowledge.

The New York Times published a huge investigative report in 2018 detailing how Trump received over $400 million from his father in ways that avoided taxes. Though he fought to prevent his tax returns from being released (instead of just voluntarily releasing them like every other president has done), the public did eventually see them. He was impeached for attempting to withhold congressionally approved military aid, as if that were personally his cash to dangle, from Ukraine. All of this information is readily available.

From public disclosure requirements, we know that his PACs are paying for his legal fees. Do his small-dollar political donors not realize that he's pocketing their money? Do they not spot the obvious contradiction by which he brags about his wealth while sending multiple fundraising emails every day?

We also know about the corruption of his insider circle, like Steve Bannon for his fraud trial regarding We Build the Wall.

Trump has created a lifetime of examples; more examples from his second presidency won't make the narrative any clearer than it already is. Many of us have been pointing out the examples for nearly a decade. At this point I don't know what piece of information, delivered in what tone of voice, could ever lead a Trump supporter to acknowledge the fact of his corruption.

I do see at the end of your essay that the citizen assembly movement and Citizens Create is intended to be an entry point to figuring out how to say things differently in conversation.