This article shows that districts that tend to vote democratic are more prosperous, and the gap is growing. However, people who are more prosperous* (income > $200k) tend to vote Republican over all. I can't explain that. If I were going to guess it would be because older people tend to have more wealth and income in America (in general) and older people sku more republican.
*https://brandongaille.com/24-interesting-republican-vs-democ...