Why has the reputation of Andrew Jackson and Woodrow Wilson (who were historically highly rated presidents) suffered so much in recent years?

Because they are being judged by a different standard now. Nowadays we have a tendency to judge historical figures not based on their era but based on the modern era.

So Woodrow Wilson was a white supremacist and a fully fledged racist. Was that much different than other men of his era? Not really. I mean see how big the KKK was at that time with millions of members across the US it’s obvious Wilson wasn’t really an exception to his era.

Was Andrew Jackson solely responsible for Indian removal and genocide? Not really. He actually negotiated with the Cherokee and the worst parts of the Trail of Tears didn’t even happen under him but his successor Martin Van Buren. Most of his contemporaries wanted the Indians removed as well hence why he was able to get the Indian Removal Act passed.

So the issue with modern day historians is that they are judging Wilson and Jackson through the lens of the modern day, rather than of their era. Past historians recognized that they were a product of their era and judged them more based on their actual accomplishments as President rather than being SJWs and seeing them as Wilson = racist! bad! Jackson = genocide! bad! that’s why they were ranked highly before but not anymore. For much the same reason now we are seeing lots of Confederate statues being removed and torn down because Americans want to remove the reminders of their ugly past. Everywhere you are seeing the past being torn down in the name of political correctness and social justice.