Jesse Jackson in 1988 could have been a very interesting candidate. His 'Rainbow Coalition' was the only real attempt I can think of in modern times to unite poor and lower middle class Americans of all races into a cause of fighting the (already) growing income inequality and it succeeded to a surprising degree (1/3 of Jesse Jackson's 6.6 million primary votes in 1988 were white.)
https://www.nytimes.com/1988/06/13/us/jackson-share-of-votes-by-whites-triples-in-88.htmlThis provides an inspiring example of Jesse Jackson's 'Rainbow Coalition':
The wide range of Jackson’s clarion call brought together former enemies in American life. Jackson recalled meeting a group of white supporters in Alabama who said, “We were with you in Selma.” After Jackson thanked them, they said, “You don’t understand, we were on the other side.”
White family farmers facing foreclosure became a key constituency of Jackson’s. Jackson explained. “The poor, white, rural farmer facing foreclosure, called himself conservative. The poor, black displaced worker, feeling rejected, called himself liberal. They were in the same situation, but they never met.”
“Economic common ground” became a refrain of the Jackson campaign, long before the “99 percent” became part of the public vernacular. “We said, ‘if we could leave the racial battleground for economic common ground, we can find the moral higher ground.’ That’s how we got the rhythm.”
https://www.thedailybeast.com/the-unsung-heroism-of-jesse-jacksonIf only Jesse Jackson had been a more credible candidate himself, who knows how he could have changed the United States.
My understanding though is that Stacey Abrams in Georgia is running a very similar 'Rainbow Coalition' campaign.