A poll of 6600 doesn't seem very "extensive" to me. The thing about these polls is you need to dig into the methodology, which for this poll can be found at:

https://www.pewsocialtrends.org/2019/04/09/race-in-america-2019/

Go down and read the "fine print", the special note about the Asian portion of the survey and you'll start seeing the problems with such definite declarations of both the article AND the polling, the "56% of all Americans think Trump has made race relations worse". They claim that the results came from online polling only, yet try to equivocate that phone surveys gave the same results. Hogwash.

As with other similar polls, you cannot trust people to give an honest answer. When I first got online, I read a statistic that a majority of people lied about themselves; their income, their happiness, their own ethics, etc. For example, when people are surveyed as to if they ever stole anything, you'd think that we're a nation of saints, but the truth is people don't like to admit to stealing, not even if the confession is done anonymously.

People will answer "It's bad." when asked about something like race relations, when in fact they think it really should get better...as it should. We would all like to live in a perfect world, but the fact is we do not and I doubt we ever will.

Polls like this pander to old prejudices and identity politics, very often not actually representing what most people really think. Answering polls and surveys is often like letters to the editor in print publications; only those upset by some issue - their objections to it real or imagined or even exaggerated - will speak up or participate in them.

I think part of that 56% are protesting against Trump's lack of tact and that of his supporters. Well, they need to get a thicker skin because many of us are tired of our critics slamming us and like Trump, we're starting to fight back. The "Silent Majority" has found its voice.