Although it would be somewhat intuitive, some of their "corrections" seem kind of funky to try to explain away the outliers to their theory.

Here in PA, we have no early voting, no same-day registration, very restrictive absentee balloting, and IDs are required, at least if you are voting for the first time or voting at a new location for the first time. We actually had a 6% increase in turnout (about 373,000+) in 2016 when compared to 2012 despite being "ranked" in the bottom 3rd of their model.

Gotta keep those black and brown people from voting.

"Mississippi has the highest percentage of black residents in the country—37 percent—and that share continues to grow as more African-Americans move south to retire. At the same time, the ratio of Latinos, though still small, has doubled from 2 to 4 percent of the population."

https://www.theatlantic.com/politics/archive/2015/01/will-a-black-latino-alliance-in-mississippi-change-politics-in-the-deep-south/431808/

Our setup/system is much like Oregon.

Aren’t they restricting Native American voters?

Not sure how this was conducted. Montana is in the middle and I find that interesting since we have easy to sign up for mail-in ballots and a good distribution of polling places. I suppose if they look at the Native American vote there are problems, both here and ND. R legislatures don't want Indians voting.

of time to fill them out and send them in.

..Due to per capita affluence and that stupid "First in the nation" BS, people here still vote.

WaPo does a few things really well, and it's really few things.

That's a fabulous graphic. Thanks!