Because the Democrats abandoned working class voters in the 80s and 90s to court the professional-managerial class in a pivot towards the center, and the Republicans were able to win over these disaffected blue-collar voters with resentment politics.
Some of them, but the Republicans still average higher income than Democrats.
The much bigger issue is that voters in general skew higher income than the general population, because working class voters are almost entirely disenfranchised.
Because the Democrats abandoned working class voters in the 80s and 90s to court the professional-managerial class in a pivot towards the center, and the Republicans were able to win over these disaffected blue-collar voters with resentment politics.
Some of them, but the Republicans still average higher income than Democrats.
The much bigger issue is that voters in general skew higher income than the general population, because working class voters are almost entirely disenfranchised.