Yes answers to the discrimination or education questions was correlated with more liberal opinions on policy (e. g., that the government should spend more on improving the conditions of blacks); a yes answer to the willpower question was correlated with more conservative opinions. A yes answer to the in-born ability question was in the middle--it had some association with conservative opinions, but not as strong as the willpower question. This may seem strange, but you can argue that people should not be held responsible for conditions that are not their fault.
Here are the figures for the proportion of blacks and whites saying yes to each question; I omit people of other races because the numbers were small. (Blacks were not asked these questions in 1977).
The proportion saying that discrimination was the main reason declined for both whites and blacks, but more for blacks. There was, however, a substantial rise between 2014 and 2016 for both races. I wonder if that resulted from the news stories and videos about police treatment of blacks in the last couple of years?
The proportion of whites who said that the differences were because blacks had less in-born ability declined substantially; the proportion of blacks increased, and has been consistently higher than the white proportion since 2000.
The proportion of whites who said that the differences were due to less chance for education declined slightly; the proportion of blacks who said this declined more substantially.
Finally, the proportion of whites who said that the differences were because blacks had less motivation declined, while the proportion of blacks rose. Opinions on this question among blacks and whites are now about the same.
To summarize, whites have become substantially less likely to say yes to the two "conservative" choices, and somewhat less likely to say yes to the two "liberal" choices. As a result, the number who said no to all rose substantially, from about 5% to over 15%. People who said "no" to all had somewhat more conservative opinions than people who answered yes to at least one, suggesting that they have sort of a fatalistic outlook--"that's just the way things are, and there's not much you can do about it."
Blacks have become more likely to say yes to the two "conservative" options, and less likely to say yes to the two liberal ones. As a result, there's been a convergence on three of them--the exception is inborn ability, which blacks are now more likely than whites to see as a reason.