I'm not entirely sure I agree with the WaPo here. I don't see anything in the data about racism being a large source of republican's voting for Trump.
The above graph, for instance, doesn't seem to support their argument, which is why I found it weird that they brought it up. What I seen in that graph is a slight decrease in racism indicators compared with 2012, putting it about on par with 2008. Nothing about that suggests there was any correlation between Trump's rhetoric causing people with even less favorable views of minorities than usual to vote.
What is quite striking, however is the huge drop off in between 2012 and 2016 in Democratic racism, which is very nice. Whether this has to do with changing viewpoints, Hillary's campaign, or the DNC's position is not known. I don't think we'll have an entirely clear idea until 2020 when we have more data.
I am going to go beyond the realm of this data for a bit, so it should be known that this is pure speculation on my part. What is possible is that
more people who had similar views on race as the generic republican voted in this election. Indeed, the stark drop off of Clinton supporters negative views on race relations could be those in the higher percentile dropping off and going to Trump's campaign. This could be the cause of his victory without moving the average too much.
I honestly can't think of an excellent way to test this, since that is talking about raw numbers rather than percentages. Perhaps a survey of voters specifically who switched from D -> R in the past election, and
their view on race relation. If we were to find a score above the Democratic average, I think that would confirm that Trump's racial rhetoric along with Hillary's more inclusive campaign, were a reason why Trump won.
In all honesty, if that is the case, I think that the democratic party can do without them. I don't need to agree with my average democratic voter on everything, bur respect for their fellow human is something I can not and will not compromise on. Racial relations are arguably the most important issue in America, and has been our entire history. The way we as a country view and treat minorities affects the country as a whole, from our support of social programs and better health care, to our willingness to go to war against people who we do not know and have never met. It is something that the democratic party needs to fight daily, and if that scares off people, so be it. I'm sure the DNC will find numbers elsewhere.
Edit: To be clear, I
do think racism played a part in Trump's win. Indeed other studies found an increase in racism causing a shift to Trump. While I had a slight problem with a number of studies methodology, I do think the sheer volume of them seems to indicate racial views played a significant part of this election. I just do not think that
this data is supportive of the argument.