If interested in the arcana, punch here. Clicking the link in the article to another essay commenting on it, helps to clarify matters. Most folks don't have a clue what the income distribution percentages are in their country, and the quantum of perceived inequality matters more in forming attitudes, than actual inequality.
Income distribution is meaningless because we can make as much wealth as we want.
The public is ignorant mainly of the consequences associated with hoarding resources. If you know the consequences of hoarding wealth, you don't need to panic. You need to figure out a way to growth wealth at the bottom end of the spectrum, without taxing wealthy people into mercantile paranoia.
Democrats fail, but they are learning slowly.