The overwhelming mainstream narrative of Doug Jones’s victory over Roy Moore in Alabama has been focused on black turnout. Here is the New York Times:
According to CNN exit polling, 30 percent of the electorate was African-American, with 96 percent of them voting for Mr. Jones. (Mr. Jones’s backers had felt he needed to get north of 25 percent to have a shot to win.) A remarkable 98 percent of black women voters supported Mr. Jones. The share of black voters on Tuesday was higher than the share in 2008 and 2012, when Barack Obama was on the ballot.
But if you actually look at the exit polling, it is pretty clear that the real story of Jones’s victory was not inordinate black turnout but rather inordinate white support for the Democratic candidate.
In the following table, I have compiled the black share of the electorate, black support for Democrats, and the election result for the 2008, 2012, and 2017 Alabama elections. These are the last three years in which this kind of exit polling exists and these are the exit polls the NYT references in the quotation above.
The black share of the electorate and black support for Democrats are virtually unchanged across the three elections, but the outcome in the last election is wildly different.
Here is the same table for white voters.
The white share of the electorate is virtually unchanged, but white support for the Democrat changes dramatically, rising all the way to 30 percent in the Jones-Moore election. This white swing towards the Democratic candidate is basically solely responsible for the fact that Jones won rather than losing by over 20 points, which is the typical outcome of a statewide Alabama election that features this level of black turnout.