On Sunday, the New York Times had a piece by Jennifer Chudy and Hakeem Jefferson on public support for the Black Lives Matter movement. They said that there had been a rise in white support for Black Lives Matter after the killing of George Floyd, but it quickly dissipated: "since last summer, Republicans and white people have actually become less supportive of Black Lives Matter than they were before the death of George Floyd — a trend that seems unlikely to reverse anytime soon." However, as a number of people who commented on the piece pointed out, views of the movement and views of issues related to racial inequality won't necessarily follow the same course.
One of the most basic issues is beliefs about the causes of racial inequality. Since the 1990s, a number of surveys (mostly by Pew), have asked people to choose between two statements: "Racial discrimination is the main reason why many Black people can't get ahead these days, black people who can't get ahead in this country are mostly responsible for their own condition." This figure shows the percent who choose discrimination minus the percent who choose "mostly responsible for their own condition."
There is a general decline in support for the "racial discrimination" option from the mid-1990s until sometime around 2010-5, and then a rise after that point. In another post, I said that the change started in 2015--looking at this figure, I would say it seems to start earlier, although that's just an impression, not the conclusion of a statistical analysis. However, either way, there was a large change before George Floyd was killed.* The strength of the public response may have been the result of this prior change in views--that is, rather than seeing it as the result of the actions of a single bad cop, people were ready to see it as one example of a larger problem.
So I think that there has been a more profound change in white attitudes than Chudy and Jefferson suggest. However, the limitation of this change is that if you believe that racial inequality is the result of discrimination against black people, the natural conclusion is that we should just stop discriminating. It doesn't necessarily result in greater support for programs that are intended to address "systemic racism"--although people use that phrase a lot these days, they usually seem to mean simply a high level of individual racism.
last survey that asked this question was completed a few days after George Floyd was killed, but most of the data was collected before. If the original data gives the exact date of the response, it would it would be interesting to look at the possible impact of his death on views.