Where are these wealthy Trump voters coming from anyways? He pretty much lost the vast majority of wealthy counties in this country (often overwhelmingly).
Despite having lost ground with them, Trump still did very well in places like Shelby County, AL, Williamson County, TN, etc. He also did well with high income voters without a college degree, which are more likely to be found in poorer counties.
Basically this. Hamilton County Indiana despite its strong D trend still gave Trump almost 60% of the vote. He also won the wealthiest county in New York, New Jersey, Colorado, Wisconsin, Ohio, Florida, (and I think most states although I haven't checked on that)