Right. Leftists don't want to appeal to white workers because they're white, but because they're workers. The Democrats have since the 1970s abandoned most of their traditional advocacy for working people. While workers of color had other urgent reasons to keep voting against Republicans, workers who didn't suffer from white supremacy switched teams or stayed home on election day.
Leftists prefer a more inclusive (or intersectional!) platform that acknowledges the relevance of class, particularly as it affects people from further marginalized backgrounds. These issues are closely interconnected, especially as right-wing demagogues like Trump and Le Pen regularly exploit economic malaise to propel themselves (and their vitriol) to higher office. A Democratic platform that is critical of capitalism, and identifies its interconnectedness with other forms of social depression, would appeal to a wider swath of people. As young voters run toward the left with no sign of slowing down, a shift toward more progressive policy will also preserve the long-term viability of the Democrats. We shouldn't chase after white workers to the exclusion of black or brown workers. Instead, Democrats need to offer sensitive and comprehensive class-based policies that appeal to all workers, regardless of race.
The worst way to appeal to white workers is somebody like Joe Manchin, a nominal Democrat with a horrible record on civil rights who
votes with the GOP on every other bill. No leftist wants this.
